Slightly curious about this event, have never been before and really really want to go but all I've really heard about bronies that go to these sort of things are the stereotypical unbelievable things.
I'm just wondering what the kind of primary age group will be? Just want to know what to expect in advance to avoid having an anxiety attack and not enjoying anything. :(
The usual crowd is around late teens, early 20s.
By stereotype, I assume you mean the people that are hyper-obsessed about the show. There are those there, but they are not the majority. You will see really high quality cosplays, but not all of those people are going to pester you about the show/fandom constantly.
I would still recommend going with someone if it is your first time. You do not want to go alone if that's what you're afraid of.