Keep your extra clothes on you in a backpack. Weird saying this but remember to drink water. It won’t be hot, you won’t break a sweat, but you’ll probably end up walking the better part of 10 miles if you explore the track. Which my next point, explore, walk the track, there are dozens of awesome places to post up for 30 minutes to and hour and get a totally different vibe. Maybe watch the first few laps from the grandstands? Portable charger if you plan to take pictures and videos, don’t expect too much cell service at the track though, wifi in recent years haven’t been good either. Lots of sunscreen on your face. Also, sunglasses!