If you are a rider of limited ability like myself, hide in the wheels, draft the living daylights out of everyone. If you find yourself on the front, get off the front and back into the wheels. Races ebb and flow, do NOT lose that wheel in front, hold on as long as possible even if it means going into your anearobic zone, once you lose contact you will be lost, with any luck the speed may slacken and you will then get your breath back. Its near the end of the season the others will be race fit and wont know who you are probably so you can get away with it.
You will learn where your weaknesses and strengths are. I am a very short uphill sprint specialist. High speed flats or long hills are not my thing. Good luck and remember its your first race, your position at the end of the day is not that important.
I take it that its a crit race by the way.