there's a bike co-op in Santa Ana on main by the performing arts highschool. its called the bicycle tree. I've never been even though I live 5 minutes away but they will definitely help you get that bike rolling for little money.
they also hold classes on everything you need to know about bicycle maintenance. you should check their website. they're also on instagram so if you're on instagram you can follow them their.

the bike doesn't look like it needs any new parts just a tune up, maybe new tires, brake pads and bar wrap.