Over here is basically a shared universe, think like what you see in Marvel or DC. Most people making characters that fit into the comic book vibe. You won't find like an Xmen OC but there is a tendency to use looks such as say Ironman to make ones own character.
Best way to start is probably to just make a character sheet in the character roster section get your ideas out there and jump into a rp once character is cleared (most are so long as it doesn't tread on history or seem broken).
I'd also recommend joining the discord server if you got it, as that's a bit more active and thus might help get acclimated all the faster