Alot of good tips , i like to add this link Programming in the Unreal Engine Architecture | Unreal Engine 5.1 Documentation .
This explains it read this and when ever you are presented with a link in the text follow it and go back and continue reading.
If you do this everything will be explained.
Also there is no need to actualy know what happens under the hood with macros like GENERATED_UCLASS_BODY() so 4th.
Save this for later when you have a better grasp on the APIs.
Also i second the tip from Pat-Level17m if you are new to UE 4 start with Blueprints. Names and logic are more or less the same for both code and BP.