Starting out, just ride. Lots. I suggest reading beginning commuter threads on the commuting forum for tips on dealing with weather, traffic, bike maintenance, carrying stuff, and securing your bike at work, school, etc. Check the touring forum for ideas on touring. With parental OK, plan some closer in trips/weekends to get used to the idea and to start figuring out what you like and what gear you will need. If you are in Boy Scouts, earn the Cycling, Camping, Hiking, and Backpacking merit badges. If your high school has an outdoors club, get involved with them to develop the same skills. By the time you're planning your big trip. you'll be ready.