I pick up some hitch hikers depending on how they look, for example woman with back pack on a free way hitchhiking is someone I would pick up, 16/18 year old boy (thats the age that I notice most kids like to cause trouble for troubles sake) with Highlights in his hair and studded leather jacket whom I occasionally glance hanging out with drunks and junkies... You HONESTLY wonder why no one would pick you up? the description you gave us is of a kid who thinks he's bigger wiser and smarter than he his (I gather this from the fact that you self proclaim that you look like your 18 and from the fact that you feel the need to point out wearing a home studded jacket) with social problems (males with highlights in their hairs tend to get beat up around here, but then again this a hunting/fishing/logging community so everyone's pretty masculine, might just be the location) who's probably been partying and could possibily have consumed alchohol or partaken in drugs, note that if you're an adult and are with a intoxicated minor then you are responsible and could go to jail. (I get this from the fact that you were out between 10:30-1:30, hell this might be why some of them felt the need to shine their brights in your eyes, to check how you responded.)
Note: I'm not saying thats what you are, I don't know you so how could I possibly say who you are? This is just what I, and most others, would put together in the 2 minutes in which they can see you on the side of the road.
Double edit note: I'm not saying all of them are completely reasonable, I have had friends who will do that shit JUST TO BE AN ASSHOLE, but meh, their cars their rules, you work for something then you don't owe anyone anything.
As for homeless, they don't just need a few dollars to get them off their feet, they need professional help and most cities that have an abundance of them have food banks, most homeless fall into that rut by being incredibly lazy and gradually learning to bum off others bit by bit. Quit their jobs, start partying commonly, lose their house, live with a friend, party more, get kicked out, go from party to party and before they know it homeless, if they really look like they are ready to start trying to turn their life around chances are you wont find them on the side of the street begging, if they 'fell on hard times' and just need some help getting back up again, there is programs for that, if they are on the side of the street with a sign and a bottle of booze, then that's their decision. I understand that situations vary from homeless to homeless, that's a pretty broad generalization and most homeless have their own reasons, and if they really look like they need the money or like they had only been on the streets for the bit I'll throw them a blanket and a bag of chips, but money is different issue, I work hard for my money and if someone wants that then they best have something they can do for me.