NextJS
Prerequisites
Before starting with next, You need to know React
Do not continue ahead if you've not read throught these sections first, your experience ahead will be very poor if you don't understand the basics.
Learn NextJS app router
We recommend using only "App Router" as it's Next's newest and most supported structure for all future releases. Detailed documentation is availble on https://nextjs.org/docs/app
Pages Router
Pages router is the old way of building apps with nextjs, it's been discontinued for use within our company, but vercel has promised to support it with no plans for deprecation.
Test your understanding
Go through this video throughly, it's very easy to write bad & low performance nextjs apps without realizing it. These are some common pitfalls with nextjs and you need to know what to use where.