Stretch, eat well, maintain your core and strengthen your back. Otherwise all your injuries will come back out in your 30’s like it did for me.
Be careful with the partying, it becomes a habit quickly.
Start putting money aside every week. Doesn’t have to be much, but put some aside anyways. I’ve been puting aside 40-70$/week since I’m 17, it builds up nicely over time.
Pay your debts quickly and get some good credit.
Travel as much as possible.