The internet can help
https://www.campgroundreviews.com/
www.rvparky.com
and some others will give some reviews for different parks, but these reviews can also be like the reviews for anything from movies to restaurants, namely angry or disappointed folks are more often motivated to leave a review than satisfied people, and some reviews are possibly from the owners. You can also use Google earth to look at a sat view of a park and get an idea of how stacked on each other some parks are.
Also a lot of material is now on you tube. Find a park in a given location and check, someone may have done a video on it, and the same can be said for destinations, if you want to visit a recreational area, there are likely a dozen or more rv'ers who have been there and done videos which include where they camped and other information on parks in the area.
Happy huntin
