ReactJS is an open-source JavaScript library used to build user interfaces specifically for single page applications.
Install nodejs: go to nodejs website and install the application
After installing nodejs go to Terminal/cmd and run node -v
to check whether it's installed correctly or not(make sure to restart you computer before running the command)
Open Terminal/cmd Run npm install -g create-react-app
This command will install react on your workstation, -g flag means global i.e you will be able to create reactjs application throughout your operating system
Run this command to create a reactjs app: create-react-app app-name
To run the reactjs application: on terminal make sure you are inside the reactjs created application (cd app-name) and than run --> npm start
After that open your browser and run http://localhost:3000/
Now you are good to go, It will show welcome to reactjs template website which you can edit and then go to it's offical website if you want to learn more about reactjs