Welcome Maxis!
Do you already know some C++? One good way to learn the kind of stuff you are trying to do is to look at Epic’s templates. You can create exact same game template in a Blueprint and a C++ version. Then you can compare the too and try to understand how the C++ version works. In the FPS template for instance in the Projectile class you’ll see how to implement collision or overlap detection. In the Character class, you’ll see how to bind and implement controls, and how to spawn objects (projectiles).
And of course there is the API documentation. First, when you don’t know what to search for, it might be a bit overwhelming, but that’s why I suggest to start by trying to understand the C++ game template projects.