command to create react app

npx create-react-app my-app
cd my-app
npm start//maske sure node js is installed on Mac
>brew update
>brew install node

>npm install -g create-react-app
>create-react-app ProjectName 
>cd ProjectName
>npm i bootstrap tachyons // for bootstrap and tachyons css libraries
>npm i react-router-dom //installing common hooks in react
>npm i firebase       // install firebase

//for import in your index.js
import 'tachyons';
import 'bootstrap/dist/css/bootstrap.min.css';
import * as firebase from 'firebase'npx create-react-app project-name