Welcome to the forum. Do a LOT of reading and research before buying any RV. Ask lots of questions.
Learn how to find evidence of leaks, a small leak can do a lot of damage if not repaired quickly.
Tires are a big issue with RV's. Many replace their tires every 5-10 years. RV tires usually age out before they wear out. Don't just look at the tread to determine tire condition. Check the actual tire age.
 
Condition is the important factor when buying a used RV. Don't be in a hurry, take your time, look at everything. Make sure the floor plan works for you.
You will find the right RV. :)