First RV Purchase

Leaks are the number one concern (to me). Wood rot can be a serious repair challenge. Look for water damage and soft spots. Typically when people talk about water damage, they're more referring to intrusion from the roof, windows, exterior lights, speakers, etc. Plumbing leaks happen too, but are not nearly as common.

I wouldn't worry about brand as much as condition and features. Try to think about how you'll use your new toy. Holding tank size might end up being important. Or ground clearance. Lots of considerations. Fun process!