Can only wish you good luck OP! No need to be nervous. Some tiny kind of anxiety or nervousness are always good though. But don't do weed/beer before the gig, please, the bigger the venue/audience the more that little will ***** you up. I played 3-4 such gigs but that was way into my "career" where I couldn't care less about the number in the audience. Bass player, back at the stage, no spotlight, just a clear eye to eye line of sight with the drummer, and monstruous monitor sound. Didn't care a **** about the audience. Didn't screw up anything, and so didn't the others. The only thing that makes me really nervous on stage, is if it's some kind of musicans I haven't play with before, but are acting very nervous, and insecure, and THEN if it's in front of a large audience on top of that. I mean, it's only the other musicians in the band that can make me go nervous. If I am with my own band, with musicians that I know will cut it, and has confidence, no audience size can tip me of in that direction. Audience reation can rub me the wrong way though, if there's a rowdy crowd, and our band has been totally misplaced for the event. But not really nervous.
It's good that you're nervous now, because that thing takes up energy, and after a while the body can't be in that mode for too long, it "concentrates" itself to other major survival things of your body. Don't force yourself to chill, and don't force yourself to be more pepped up than you are. Just go along in neutral gear. You will cool down the closer it comes.
More often than not, after the first number, it's all out of your system, and the gig will cruise a breeze.
