Replying to Anyone with a crotch rocket

I'm thinking its about time I get one.  I've wanted one forever and I'll finally be making some money this summer so yeah. I've never driven one, but I do drive a manual so I know exactly how a clutch/shifting works so I'm not too worried about that.  Couple of questions though:

1. What should I be looking for?  I don't want anything crazily powerful and actually I wouldn't mind just having a 250cc bike, but I don't think there are a lot of choices as far as those go.  So either a 250cc or one step up from that.

2. Parents. I'm 20 and I'd be paying for the whole thing myself, but they could stop me by cutting my college funding :/

3. Safety class?  Might help convince my parents/I wouldn't mind a little instruction, but it takes a lot of time and it looks like they're full till june.  I don't really wanna get one in the middle of summer, that's a waste.

Any help? Suggestions? Anything?

I'd be taking a loan out and I don't think I wanna spend anymore than 5k so that kinda limits me, but it would be a first bike and one for learning on. Thanks.