I see you're having an adventure. Ahhh to be young again. As far as fixing brakelines is concerned: If you don't have the tools, don't bother. I've done plenty of auto repair on many a junker in my time and getting the wheel wells off is a pain all in its own right. As far as insurance goes, you can always register a mailbox with somebody like the UPS store and then have it transferred later when you find a place to settle down. As far as earning cash, Muskogee should still have a temp agency (it's been many years since I've been there). Or you could always look for a place like Liberty Financial or similar tax business. They pay $10/hr to hold a sign for 12hrs. and aren't too fussy about return laborers (it'll get your brake lines fixed and maybe a sandwich in your gut). If I had read this a week or two ago, I would have offered to see an arrangement. As it stands, I won't have cash to blow on willy nilly for a couple of weeks. If you're still stuck in Muskogee in 2 weeks time, I would be happy to work out a means to exchange currency for items on good faith.
Don't give up on your road trip. You'll look back on this when you're older and smile. Trust me, what sucks today is hilarious tomorrow.