what I am understanding with module not found is please check you imports and exports of the files and the file path. Also it is polyfill node core modules error because current version of webpack no longer includes NodeJS polyfills by default it is causing issues for devellopers when the use web3.js.
steps toresolve this error
2>Install missing dependencies
3>Override the create-react-app webpack config file.
4>Override packege.json to include the webpack configuration