If you're just coming off of high school, it's socially acceptable to delay starting University by a semester or two to go backpack around the world for a while. If you can scrape together a few grand to do so, definitely jump on the chance.
Fly one-way to Bangkok, get a room on Ko San road, then walk downstairs and grab a beer in the bar. Talk to people, ask where they've been and where they're going. Ten minutes of this will probably be enough to load you up with 6 months worth of amazing things to do in SE Asia.
It's cheap there. It's easy to get around. The locals are friendly and speak English. You'll rock it.
Fly out, say, tomorrow afternoon (or the day after you graduate, if you haven't yet done so). Stay as long as the money holds out. Use your last $600 to buy a one-way flight home from wherever you happen to have ended up.
You'll come back never having to ask strangers for a list of new thing to try again.
Good luck!