GET IN SHAPE
Before the race:
Practice sitting on wheels, patching & changing hose, eating and drinking on the bike. You should eat before you get hungry and drink before you get thirsty.
Eat well the day before the race so that the body is max filled up.
During the race:
Make sure your bike is in order. The chain is lubricated, tires pumped, and not too worn, the brakes work. Ride with a helmet, also during training. Remember pump & patchwork, as well as a multitool, so you can handle most things. Remember lights and rainjacket. Creditcard, phone, charger.