Solution 1 :

html {
    height: 100%;
  }
  body {
    margin:0;
    padding:0;
    font-family: sans-serif;
    background: linear-gradient(#141e30, #243b55);
  }
  
  .login-box {
    position: absolute;
    top: 78%;
    left: 50%;
    width: 400px;
    padding: 30px;
    transform: translate(-50% , -50%);
    background: rgba(0,0,0,.5);
    box-sizing: border-box;
    box-shadow: 0 15px 25px rgba(0,0,0,.6);
    border-radius: 20px;
  }
  
  .login-box h2 {
    margin: 0 0 30px;
    padding: 0;
    color: #fff;
    text-align: center;
  }
  
  .login-box .user-box {
    position: relative;
  }
  
  .login-box .user-box input {
    width: 100%;
    padding: 10px 0;
    font-size: 16px;
    color: #fff;
    margin-bottom: 30px;
    border: none;
    border-bottom: 1px solid #fff;
    outline: none;
    background: transparent;
  }
  .login-box .user-box label {
    position: absolute;
    top:0;
    left: 0;
    padding: 10px 0;
    font-size: 16px;
    color: #fff;
    pointer-events: none;
    transition: .5s;
  }
  
  .login-box .user-box input:focus ~ label,
  .login-box .user-box input:valid ~ label {
    top: -20px;
    left: 0;
    color: #03e9f4;
    font-size: 12px;
  }
  
  .login-box form a {
    position: relative;
    display: inline-block;
    padding: 10px 20px;
    color: #03e9f4;
    font-size: 16px;
    text-decoration: none;
    text-transform: uppercase;
    overflow: hidden;
    transition: .5s;
    margin-top: 40px;
    letter-spacing: 4px
  }
  
  .login-box a:hover {
    background: #03e9f4;
    color: #fff;
    border-radius: 5px;
    box-shadow: 0 0 5px #03e9f4,
                0 0 25px #03e9f4,
                0 0 50px #03e9f4,
                0 0 100px #03e9f4;
  }
  
  .login-box a span {
    position: absolute;
    display: block;
  }
  
  .login-box a span:nth-child(1) {
    top: 0;
    left: -100%;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, transparent, #03e9f4);
    animation: btn-anim1 1s linear infinite;
  }
  
  @keyframes btn-anim1 {
    0% {
      left: -100%;
    }
    50%,100% {
      left: 100%;
    }
  }
  
  .login-box a span:nth-child(2) {
    top: -100%;
    right: 0;
    width: 2px;
    height: 100%;
    background: linear-gradient(180deg, transparent, #03e9f4);
    animation: btn-anim2 1s linear infinite;
    animation-delay: .25s
  }
  
  @keyframes btn-anim2 {
    0% {
      top: -100%;
    }
    50%,100% {
      top: 100%;
    }
  }
  
  .login-box a span:nth-child(3) {
    bottom: 0;
    right: -100%;
    width: 100%;
    height: 2px;
    background: linear-gradient(270deg, transparent, #03e9f4);
    animation: btn-anim3 1s linear infinite;
    animation-delay: .5s
  }
  
  @keyframes btn-anim3 {
    0% {
      right: -100%;
    }
    50%,100% {
      right: 100%;
    }
  }
  
  .login-box a span:nth-child(4) {
    bottom: -100%;
    left: 0;
    width: 2px;
    height: 100%;
    background: linear-gradient(360deg, transparent, #03e9f4);
    animation: btn-anim4 1s linear infinite;
    animation-delay: .75s
  }
  
  @keyframes btn-anim4 {
    0% {
      bottom: -100%;
    }
    50%,100% {
      bottom: 100%;
    }
  }
  
.section-container {
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    text-align: left;
    width: 100%;
    background-image: linear-gradient( 60deg, rgba(57, 60, 90, 0.85), rgba(180, 180, 120, 0.5) );
    background-position: center;
    background-size: cover;
    font-weight: bold;
    text-shadow: rgb(56, 50, 50) 1px 1px
}

.title-container {

    display: block;
    color: white;
    text-shadow: 2px 2px black;
    width: 40%;
    padding: 30px;
    margin-bottom: 20%;
    margin-right: 50px;
    border-top: 1px black solid;


}
<div class="login-box">
        <h2>Login</h2>
        <form>
          <div class="user-box">
            <input type="text" name="" required="">
            <label>Username</label>
          </div>
          <div class="user-box">
            <input type="password" name="" required="">
            <label>Password</label>
          </div>
          <a href="#">
            <span></span>
            <span></span>
            <span></span>
            <span></span>
            Submit
          </a>
        </form>
      </div>

      <div class="section-container">
        <h2 class="title-container">Here are my other socials you can find me on
        </h2>

        <img src="https://placekitten.com/150/150" alt="">Image 

      </div>

Not a css issue. You don’t have the correct path to the image. I’ve inserted the correct path.

Solution 2 :

The margin on the heading element is causing this.
Instead of adding the img element, consider adding the image as a background to another element…

CSS added:

body {
  background: url("//placekitten.com/150/150");
  background-repeat: no-repeat;
  background-size: cover;
}

Below I have added it to the body, but this could be done to any element of your choosing really.

html {
  height: 100%;
}

body {
  margin: 0;
  padding: 0;
  font-family: sans-serif;
  background: linear-gradient(#141e30, #243b55);
}

.login-box {
  position: absolute;
  top: 78%;
  left: 50%;
  width: 400px;
  padding: 30px;
  transform: translate(-50%, -50%);
  background: rgba(0, 0, 0, .5);
  box-sizing: border-box;
  box-shadow: 0 15px 25px rgba(0, 0, 0, .6);
  border-radius: 20px;
}

.login-box h2 {
  margin: 0 0 30px;
  padding: 0;
  color: #fff;
  text-align: center;
}

.login-box .user-box {
  position: relative;
}

.login-box .user-box input {
  width: 100%;
  padding: 10px 0;
  font-size: 16px;
  color: #fff;
  margin-bottom: 30px;
  border: none;
  border-bottom: 1px solid #fff;
  outline: none;
  background: transparent;
}

.login-box .user-box label {
  position: absolute;
  top: 0;
  left: 0;
  padding: 10px 0;
  font-size: 16px;
  color: #fff;
  pointer-events: none;
  transition: .5s;
}

.login-box .user-box input:focus~label,
.login-box .user-box input:valid~label {
  top: -20px;
  left: 0;
  color: #03e9f4;
  font-size: 12px;
}

.login-box form a {
  position: relative;
  display: inline-block;
  padding: 10px 20px;
  color: #03e9f4;
  font-size: 16px;
  text-decoration: none;
  text-transform: uppercase;
  overflow: hidden;
  transition: .5s;
  margin-top: 40px;
  letter-spacing: 4px
}

.login-box a:hover {
  background: #03e9f4;
  color: #fff;
  border-radius: 5px;
  box-shadow: 0 0 5px #03e9f4, 0 0 25px #03e9f4, 0 0 50px #03e9f4, 0 0 100px #03e9f4;
}

.login-box a span {
  position: absolute;
  display: block;
}

.login-box a span:nth-child(1) {
  top: 0;
  left: -100%;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, #03e9f4);
  animation: btn-anim1 1s linear infinite;
}

@keyframes btn-anim1 {
  0% {
    left: -100%;
  }
  50%,
  100% {
    left: 100%;
  }
}

.login-box a span:nth-child(2) {
  top: -100%;
  right: 0;
  width: 2px;
  height: 100%;
  background: linear-gradient(180deg, transparent, #03e9f4);
  animation: btn-anim2 1s linear infinite;
  animation-delay: .25s
}

@keyframes btn-anim2 {
  0% {
    top: -100%;
  }
  50%,
  100% {
    top: 100%;
  }
}

.login-box a span:nth-child(3) {
  bottom: 0;
  right: -100%;
  width: 100%;
  height: 2px;
  background: linear-gradient(270deg, transparent, #03e9f4);
  animation: btn-anim3 1s linear infinite;
  animation-delay: .5s
}

@keyframes btn-anim3 {
  0% {
    right: -100%;
  }
  50%,
  100% {
    right: 100%;
  }
}

.login-box a span:nth-child(4) {
  bottom: -100%;
  left: 0;
  width: 2px;
  height: 100%;
  background: linear-gradient(360deg, transparent, #03e9f4);
  animation: btn-anim4 1s linear infinite;
  animation-delay: .75s
}

@keyframes btn-anim4 {
  0% {
    bottom: -100%;
  }
  50%,
  100% {
    bottom: 100%;
  }
}

.section-container {
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  text-align: left;
  width: 100%;
  background-image: linear-gradient( 60deg, rgba(57, 60, 90, 0.85), rgba(180, 180, 120, 0.5));
  background-position: center;
  background-size: cover;
  font-weight: bold;
  text-shadow: rgb(56, 50, 50) 1px 1px
}

.title-container {
  display: block;
  color: white;
  text-shadow: 2px 2px black;
  width: 40%;
  padding: 30px;
  margin-bottom: 20%;
  margin-right: 50px;
  border-top: 1px black solid;
}

body {
  background: url("//placekitten.com/150/150");
  background-repeat: no-repeat;
  background-size: cover;
}
<div class="login-box">
  <h2>Login</h2>
  <form>
    <div class="user-box">
      <input type="text" name="" required="">
      <label>Username</label>
    </div>
    <div class="user-box">
      <input type="password" name="" required="">
      <label>Password</label>
    </div>
    <a href="#">
      <span></span>
      <span></span>
      <span></span>
      <span></span> Submit
    </a>
  </form>
</div>

<div class="section-container">
  <h2 class="title-container">Here are my other socials you can find me on
  </h2>

</div>

Problem :

I am not able to run my code and produce an image under header 2

Are there any reason why as I have already input the right code.

I believe another css layout is blocking the image from popping out. Below here is the code to check

<div class="login-box">
        <h2>Login</h2>
        <form>
          <div class="user-box">
            <input type="text" name="" required="">
            <label>Username</label>
          </div>
          <div class="user-box">
            <input type="password" name="" required="">
            <label>Password</label>
          </div>
          <a href="#">
            <span></span>
            <span></span>
            <span></span>
            <span></span>
            Submit
          </a>
        </form>
      </div>

      <div class="section-container">
        <h2 class="title-container">Here are my other socials you can find me on
        </h2>

        <img src="//placekitten.com/150/150" alt="">Image 

      </div>

My CSS below

html {
    height: 100%;
  }
  body {
    margin:0;
    padding:0;
    font-family: sans-serif;
    background: linear-gradient(#141e30, #243b55);
  }
  
  .login-box {
    position: absolute;
    top: 78%;
    left: 50%;
    width: 400px;
    padding: 30px;
    transform: translate(-50% , -50%);
    background: rgba(0,0,0,.5);
    box-sizing: border-box;
    box-shadow: 0 15px 25px rgba(0,0,0,.6);
    border-radius: 20px;
  }
  
  .login-box h2 {
    margin: 0 0 30px;
    padding: 0;
    color: #fff;
    text-align: center;
  }
  
  .login-box .user-box {
    position: relative;
  }
  
  .login-box .user-box input {
    width: 100%;
    padding: 10px 0;
    font-size: 16px;
    color: #fff;
    margin-bottom: 30px;
    border: none;
    border-bottom: 1px solid #fff;
    outline: none;
    background: transparent;
  }
  .login-box .user-box label {
    position: absolute;
    top:0;
    left: 0;
    padding: 10px 0;
    font-size: 16px;
    color: #fff;
    pointer-events: none;
    transition: .5s;
  }
  
  .login-box .user-box input:focus ~ label,
  .login-box .user-box input:valid ~ label {
    top: -20px;
    left: 0;
    color: #03e9f4;
    font-size: 12px;
  }
  
  .login-box form a {
    position: relative;
    display: inline-block;
    padding: 10px 20px;
    color: #03e9f4;
    font-size: 16px;
    text-decoration: none;
    text-transform: uppercase;
    overflow: hidden;
    transition: .5s;
    margin-top: 40px;
    letter-spacing: 4px
  }
  
  .login-box a:hover {
    background: #03e9f4;
    color: #fff;
    border-radius: 5px;
    box-shadow: 0 0 5px #03e9f4,
                0 0 25px #03e9f4,
                0 0 50px #03e9f4,
                0 0 100px #03e9f4;
  }
  
  .login-box a span {
    position: absolute;
    display: block;
  }
  
  .login-box a span:nth-child(1) {
    top: 0;
    left: -100%;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, transparent, #03e9f4);
    animation: btn-anim1 1s linear infinite;
  }
  
  @keyframes btn-anim1 {
    0% {
      left: -100%;
    }
    50%,100% {
      left: 100%;
    }
  }
  
  .login-box a span:nth-child(2) {
    top: -100%;
    right: 0;
    width: 2px;
    height: 100%;
    background: linear-gradient(180deg, transparent, #03e9f4);
    animation: btn-anim2 1s linear infinite;
    animation-delay: .25s
  }
  
  @keyframes btn-anim2 {
    0% {
      top: -100%;
    }
    50%,100% {
      top: 100%;
    }
  }
  
  .login-box a span:nth-child(3) {
    bottom: 0;
    right: -100%;
    width: 100%;
    height: 2px;
    background: linear-gradient(270deg, transparent, #03e9f4);
    animation: btn-anim3 1s linear infinite;
    animation-delay: .5s
  }
  
  @keyframes btn-anim3 {
    0% {
      right: -100%;
    }
    50%,100% {
      right: 100%;
    }
  }
  
  .login-box a span:nth-child(4) {
    bottom: -100%;
    left: 0;
    width: 2px;
    height: 100%;
    background: linear-gradient(360deg, transparent, #03e9f4);
    animation: btn-anim4 1s linear infinite;
    animation-delay: .75s
  }
  
  @keyframes btn-anim4 {
    0% {
      bottom: -100%;
    }
    50%,100% {
      bottom: 100%;
    }
  }
  
.section-container {
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    text-align: left;
    width: 100%;
    background-image: linear-gradient( 60deg, rgba(57, 60, 90, 0.85), rgba(180, 180, 120, 0.5) );
    background-position: center;
    background-size: cover;
    font-weight: bold;
    text-shadow: rgb(56, 50, 50) 1px 1px
}

.title-container {

    display: block;
    color: white;
    text-shadow: 2px 2px black;
    width: 40%;
    padding: 30px;
    margin-bottom: 20%;
    margin-right: 50px;
    border-top: 1px black solid;


}

I tried to put the img code under . but did not get the image to pop up under the h2 tag

Comments

Comment posted by Wayne Celestin

Adding an alt text would be useful too, in case their is an issue with the link.

By