If you're near the pole and the wifi is still bad, then the campground wifi sucks and nothing you can do will help it.
The best way of testing it is to literally take your laptop or device and stand directly beside of the park wifi access point. If it's good there, but bad in your RV- then you can help it. If it's bad there, there's nothing you can do.
See if this helps:
Learn To RV: Cellular, wifi, and networks - OH MY!