Welcome to the forums!

Best advice I can give you is to not just buy the first gun you see or hear about. Try to get to a walkon and mingle and ask people. Ballers LOVE to show off their kit, and I know if someone approaches me politely and asks, I would have no probs letting you have a shot over the chrono. Be polite and ask about mate, get a good feel for milsim, tournament, magfed markers and make a decision around that.
First things first though, get yourself a decent mask! Thats your most important bit of kit.