So… I’m back 
I worked through your info which helped me a lot (again, thank you) but now I’ve a very specific issue which might be a good example of the kind of problems I’m struggeling to grasp. Again I’m not nesscesarily looking for a solution for this single problem, but I want to reach a point where I can solve this myself. Maybe you have some more ressourced for that?
Let me describe you the issue at hand: I tinkered around some more and stumbled across the Gameplay Ability System. I followed some tutorials to implement it and it works as expected. But now I want to do more. For example from my test-ability blueprint I would like to reach a function that is implemented in my character - or going even further I would like to reach a functionality that is provided by a different component that is added to my character. I know there is some sort of “connection” because the ability can eg trigger animations on my character - but how does this work?
This is a prime example of the part I just don’t really get. How would something like this GAS_Ability be connected to my character that is calling this ability. And how would I navigate this connection. And most importantly: How would I find out myself what type of connection I’m dealing with the next time I’ve an issue reaching some functionality?