If you want to learn "Wi-Fi fundamentals" I think you're better served by ignoring Arduino completely and just learning how things work at the server/protocol level. There are many such examples at all levels of understanding. It sounds like you want to understand how to use Wi-Fi, not necessarily how all the IP layers work.
So maybe find a basic internet tutorial like 24.1. How the Internet Works — Introduction to Professional Web Development in JavaScript documentation
Then I'm guessing you may be stuck on some of the arduino web page tutorials.
This should be a good start to understand web pages: How to create dynamic HTML pages ? - GeeksforGeeks
Or maybe I'm completely wrong about what you're asking 