First, let's talk research. Since outlaw Motorcycle Clubs are a very specific type of group, they're expected to behave in particular ways. "The Sons of Anarchy" is a TV series that portrays bikers somewhat accurately, from what I gather. There are also many books out there - Kaz read "Under and Alone" by William Queen, which tells of his experience in the Mongols MC as an undercover agent. There are a few websites that address outlaw MC etiquette and rules. You can also just ask us, as we don't follow those things religiously. They are a good starting point though.
Your character must be human. NO vampires, zombies, ghosts, werewolves, ghouls – all that stuff. No supernatural abilities please.
A guy. Most outlaw MC's are men. He can be straight, bi, or gay. We feel that sort of thing is personal and not to be dictated. (You, the real person, can be man or woman or in transition or whatever.)
Age-wise 21 years old to... I dunno, however old that he can still ride his motorcycle a