Godot 4.0 is pre-alpha software. It is not ready for use, and does not work in the same way as 3.x. You should not be using it if you are a beginner.
I hear what you are saying but there are many reasons to begin with the latest beta version of a software product. Regardless of whether or not the user is a beginner, there is nothing wrong with asking for clarifications about differences between versions. If anything, I believe these kinds of questions help both users of the product, and developers seeking to improve the software and documentation.