Seriously, just GO DO something. If you think you should be doing something, just GO. You'll be tired, you'll want to stay in bed. But the bed will be there, the internet will be there when you get back (if when you get back, you care about looking at it at all).
If you have a gut feeling, don't ignore it. It may turn out that you were slightly over-reacting, but if you weren't- you won't regret it.
Schools don't teach you everything. Neither do parents. The hardest lessons you will learn will be from your peers and your heroes and in the most unexpected of places.
Luckily, our family does kick ass, and will always be there for you.
Seek out your own spirituality.
Brush daily and floss (a lot).
Embrace nature. There are only small bits of it left. Listen, be still, and absorb.
Mixing beer and liquor. Just, don't.
Find an active pursuit you love, and do it 3 or more times a week. The youngest looking people I know all have this in common. (Skiing, skateboarding, yoga, karate/martial arts [just not the punching in your face kind.].)
"the more I see, the less I know" But that doesn't have to stop you from trying to know more, to see more.
Travel, travel, travel.
Talk to people. It gets easier, but you never know who you will meet.