Youngin's on the road
I guess this is the reason I got on this thing, seein' as I didn't see this particular advice given...
For you dear underage things gettin' out on the road (note: This ain't directed at runaways, I am a firm believer, through experience, that unless extreme circumstances are at hand, you should trust yer' parents, talk to them like a mature, civilized person about what you'd like to do, why you want to do it and how intelligent and safe you'll be, and if they still tell you no, it's probably for the best- give 'em credit for the ample amount of experience they hold over you, and wait 'til your legally aloud to leave the nest. Breaking your parents heart ain't anything fun and if you have a soul, you'll live to regret it.)
Anyway, if your parents are alright with you traveling, a really amazing thing to do that will make your, your parents, and whoever you're hanging out with and/or traveling withs life a lot easier is- have your parent quickly write out a letter saying "I, (name), give my child (your name) permission to... yada, yada, yada (if you're traveling with someone of age it's good to have them entrusted with you somehow)", it's really only a short little paragraph, then they can go to a bank, post office, city building or other place and sign it and have it notarized, for free. You take that handy piece of paper along on your trip and whip it out when your being hassled and you will save yourself the grief, keep whoever your with out of a good chunk of trouble and ensure that you don't give your parents a panic disorder being called by police all the time!
And be safe! Don't do stupid shit! Call your mother often and let her know you love her!