when is the race?
hills - go up them hard, dont worry about "blowing up", the important thing is hanging with the pack. be very near or even on the front, that way if you start to slow, you can hopefully latch onto the back of a group going over the top and not end up off the back.
descents - try to recover, stay upright, I descend like a bowling ball and like being up front so I can choose my path.
training - its generally better to be well rested and somewhat undertrained than tired.
go practice your cornering/turning. alot. until you feel confident in how the bike feels when you're turning.
good luck in your race.