Sounds like you've got the right spirit! I remember that I couldn't sleep before my first match. As long as you have some kind of holster, I've seen plenty of guys pull mags from their pants pockets. As long as you're safe about it, no one will care.
I started with an M&P 9mm in one of...
It's your first match. Don't worry about speed or accuracy. Just worry about knowing/following the RO commands. Speed will come with time. Even if you walk your first match and shoot each target slowly like you're in a bullseye match, no one is going to yell at you to hurry up. If you run...