Steps:

[+] Create NPM project 
terminal: npm init -y

[+] Create Index, Css, Js files

[+] Install dependancies. express, nodemon(dev dep.)
terminal: npm install express
terminal: npm install nodemon -D

[+] Create a express server (server.js)
terminal:npm run dev( for test host:3000)

[+] do frontend part

[+] Install socket.io, Setup socket.io in server.js and client client.js

[+] Client send message logic in client.js

[+] Recieve message on server and broadcast to all clients

[+] Recieve message on client and display it. scrollToBottom etc...