Start with Node Express Backend

 First Create a folder where you want to make backend and frontend

Go to Backend folder and and run npm init -y this will create package.json file in your backend directory.

Next step is in your backend folder install some package like below-

express - Main backend framework

cors - Cross Origin Resource Sharing (This will allow frontend for data)

dotenv - .env file variable load karne ke liye

body-parser - Request body json parse karne ke liye.

Single command to install thease package-

npm install express cors dotenv morgan body-parser

after running above command package.json me dependencies section me ye package dikhenge.