Epic’s multiplayer system for the most part is pretty reasonable - it abstracts quite a lot of the *true horror *of writing multiplayer code away and wraps it all within a few different concepts as part of it’s ‘Replication’ model.
Fact of the matter is that multiplayer is just plain more difficult that singleplayer and it’ll take time to wrap your head around most of the concepts. Best place to start is to start small, and the best way to learn is simply by doing. There are no shortcuts.