The best thing to do is ride sand before hand. Rollers all the time and carry your front wheel from top to top. Get a sand tire for sure, and don't be surprised if you get smoked by someone on a clapped out two stroke that you never heard of before because it's probably a local that rides there all the time.
Not sure how far Supercoop is for you, but once they get going they run practice all the time, and it's sand sand sand. Start planning Saturday trips there for their open practice and stay all day as the track changes from a smooth sand boulevard to a nasty sand pothole laden course over the course of a day.
Motoland in Indiana has a practice weekend on June 8-9 before then, plan to go there and ride too. It's sand and usually split into two tracks, and you ride 20 minutes on one, 20 minutes off, 20 minutes on the other one, 20 minutes off, and back to 20 minutes on the first one all day. It's great training to pound out those 20 minute motos every 20 minutes all day. It's all sand and you can check out how sand tires perform there.