You need to bring your car in good working mechanical order, a valid driver's license and a helmet (loaner helmets are available in most regions). You may also want to bring a tire pressure gauge, multiple layers (coat, sweat shirt, sweat pants) gloves, a cooler (water, pop/soda, sports drink, lunch), comfortable shoes, towels, rain gear, sun block, a hat and anything else that you would want for a day spent outdoors.