If you have access to news stands selling international magazines, and read languages other than English, I suggest:
In French,
"L'essentiel du Camping-car" which usually has destinations in every issue.
"Le Monde du Camping-Car" which publishes special issues like "Vacances en Camping-Car" which include where to go, what to see, where to camp, and may include fairly complete lists of camping and RV parking places (in France there is a distinction) for the country covered.
In Spanish,
"Super Caravaning & Camping" for which each issue should have a few trip ideas, destinations, and maybe campground reviews.
In German,
"Reise Mobile International" which I think is a German magazine, though I bought it in Salzburg. This tends to focus more on the motorhomes and technology, but should have at least a couple destination articles, and contains a fair-sized section of classified adverts that include resorts and campgrounds.
I have not picked up any RV magazines in Portugal, Italy, the Netherlands, nor the Scandavian or Baltic states, nor Poland, Hungary, Czech Republic or Slovakia, because I do not read those well enough to make the purchase worthwhile to me.
But in those places I have kept my eyes open for RVs and campgrounds, learning what to expect where, as it is different as you travel through Europe, just as it is in different parts of the U.S. For example, in the agricultural areas of France, I found that towns maintain camping places for seasonal workers traveling for planting and harvest, much like those I find across our agricultural heartland. Different from those places where families go to vacation. Also, in the south of Spain, you will find "snowbird" areas where seniors move to escape winter, much like those we have in our southwestern deserts, South Texas, and South Florida. But in Europe, there is also a North Africa option, which might be comparable to our going into Mexico for the winter.