www.workcamping.com is one place to look. Do a search for workcamping and you should see blogs and websites with information. National Parks and Forest Service campgrounds hire lots of folks as well as privately owned campgrounds. I have a friend returning for year # 2 at Adventureland (Amusement park) in Iowa as a workcamper.
Please carefully research the financial requirements to purchase, maintain, travel in and to stay in your chosen RV. It is agreat lifestyle but sometimes it is not cheaper.
Good luck!!