I thought it'd be a huge deal when I came out, too, but honestly I don't remember a single person ever even bringing it up (aside from friends, and not in any negative ways), people don't really care who you are into, at least they shouldn't. If it does become a problem and need some one to talk to, there are several users including myself who wouldn't mind you shooting a
PM our way.
As for groups I wouldn't know, our school didn't either and there weren't any groups outside of it either since I come from a very small town. I guess making other
lgbt friends online might be an option, if you can't find any groups nearby? Grats on being comfortable enough to come out!