Since the OP started this post asking about campgrounds and this has now gone more toward types of RVs, etc. I want to point out to the OP that many campgrounds will not allow one to put a mini-van and a tent on a site. Some campgrounds do have tent sites but these are just for tents and the van or car is parked not on the site. Some will not allow a van other than one used just for transportation that does not have "facilities" - water, electricity, etc. They really don't want someone pulling in and sleeping in their van with a mattress on the floor. This is something to consider in your deciding what you want for an RV and how you will travel with it.
There are conversion vans such as the Roadtrek, Pleasureway, and others that are full motorhomes inside of a van. Because of what is involved in building this commercially, these tend to be the higher price range of RVs. Of course, one can convert one's own van - but as I say, to go into a campground with it the conversion will have to include motorhome facilities.
For what you are looking to do, you would best in a small trailer or popup. There are trailer pop ups where the top is a tent and there are some facilities inside. I have seen many of these at campgrounds so that would not be an issue. These will be your least expensive way to go and you can use your mini-van to tow it.
