legal shit, cultural shit, that sort of thing
Started at 17 but went went with close friends. I imagine 19 would be more than fine so long as you're street smart and have previous travel experience. Have fun OP, report back if anything cool happens.
Im doing petty traveling with family members across the US, I was in California all my life then New Mexico at 18 and now at 19 im in Texas, im thinking in a year or two im going to be headed for Virginia. get a decent job, and then travel to another country. So im actually having these thoughts too mane, where you from ?
I'm in exactly the same position, 19, travelling alone to Japan in June. As long as I can get a basic grasp on the language before then, I'll be ok. May as well go when you're young enough to still score 17 year olds. I don't drink so being underage is no problem for me. Keep that in mind though.
I've met people who were 19/20 several times. Being a few years older won't change how safe a place is. Just do the basic preparations: research where you're going, learn some basics of the language and customs.
I travelled around Europe when I was 19 without any major problems. Most people I met in hostels were a few years older or more however (and in some of the more obscure cities I visited everyone was 30+). Seems a lot of Europeans travel around the continent after finishing university.
I went hitchiking around as soon as I turned 18. Not much to worry about. Just like people here were already saying. You have to know some basic street smarts (try not to stumble in some dangerous areas in city at night when you're alone.)