Make sure your bike is shifting properly and nothing is loose or rattling. Check tire pressure and set your bike in the right gear for the start of the race. Take the first 10 miles out easy, and ease into the ride. Remember to eat/drink during the ride.
Warm up for 5-10' before the race and stay loose and calm. Go over your race day plan in your head. Feel strong and confident.
Warm up for 10' and race a 4.2k - (warm up for at least 500 yds) - if you can - throw in a few 50s - just to get your HR up and ready to race from the get go! Pick a straight line, get on some fast feet and Good Luck!