In addition to the above links, Pantong51 has gathered some additional resources which should redirect you to more content.
You’re going to need to be well-versed in C++ in order to properly use it. I don’t think it’s something you could go through while you’re still learning, unless you limit yourself to just implementing simple abilities and effects while leaving most of the replication, tasks, and finer details alone. Even then, it might be a lot of trial and error before you get something working.
I wouldn’t recommend using it for small mobile games if you’re making games alone unless you already know how to implement it, and even then it seems a little overkill.
I’d consider using it if I plan on having many abilities and effects, multiple characters, tons of character stats, and/or if I want its replication to build upon. It really is a powerful system.
That shouldn’t stop you going through it at least if you’re not under some deadline. Cherry-pick something you don’t understand and look it up, just don’t let it confuse what you’ve already learned.