Exercise - helps you think better, helps you feel better, helps you emotionally. Find something you like doing - I do power lifting and yoga - and get in the habit of doing it daily.
Explore - odds are your career isn’t really going to take off until your late 20s at the earliest, because frankly until then you’re just not going to be very good. Spend the time to learn everything you can from everyone you can and try anything you can - experience now pays dividends later. Accept that you’re young and inexperienced, be humble, don’t pretend you know what you’re doing when you don’t, and you’ll come out of this decade miles ahead of where you start.
Oh, and - you’ve got 60 years ahead of you, statistically speaking. Probably no more, probably no less. Plan accordingly.