Check this one hope you create react app

1 check your nodejs version

node -v

2 check your npm version

npm -v

3.you globally installed your react app

4.Go terminal and root path

npx create-react-app appname

1. Uninstall the [nodejs] (https://nodejs.org/en/download/)!
2. Install it again

it works I have tried it.

$ npx create-react-app robot
npx: installed 67 in 583.936s

Creating a new React app in C:UsersUserReactAppsrobot.

Installing packages. This might take a couple of minutes.
Installing react, react-dom, and react-scripts with cra-template…

npm ERR! code ECONNRESET
npm ERR! errno ECONNRESET
npm ERR! network request to https://registry.npmjs.org/querystring/-/querystring-0.2.0.tgz failed, reason: socket hang up
npm ERR! network This is a problem related to network connectivity.
npm ERR! network In most cases you are behind a proxy or have bad network settings.
npm ERR! network
npm ERR! network If you are behind a proxy, please make sure that the
npm ERR! network ‘proxy’ config is set properly. See: ‘npm help config’

npm ERR! A complete log of this run can be found in:
npm ERR! C:UsersUserAppDataRoamingnpm-cache_logs2021-01-21T18_37_39_680Z-debug.log

Aborting installation.
npm install –save –save-exact –loglevel error react react-dom react-scripts cra-template has failed.

Deleting generated file… package.json
Deleting robot/ from C:UsersUserReactApps
Done.