I can see several issues there, and the way you set it up also breaks many programming rules.
I have no idea what kind of research you are doing, but those resources aren’t helping you at all.
If you break the rules and the program still works, then you will have trouble with code optimization. If you break the rules and the code does not work, then it’s just bad code overall.
To start, your conceptual understanding of using the class interface appears to be far off. Also, I can see a lot of the issue is actually coming from blueprint communication setup. The best thing that I can tell you calling an interface event always needs an address target. A receiver, otherwise your messages will not be sent correctly.