Not much "in town." There are a couple of private campgrounds around the south side of the Twin Cities. They are listed in directories and apps like AllStays and RV Parky. Also St. Paul East RV Park is listed. Never been there so no info, sorry.
There is no camping at Ft. Snelling SP or the nearby National Wildlife Refuges. There is no RV camping (only hike or canoe in) at Afton SP. St. Croix SP has lots of RV camping including many electric sites.
Please note that all MN SP's have gone to 100% reservations. Meaning no spaces are held out for walk-ins. You may still find spaces on a walk-in basis but you still have to reserve them from the park; if someone else reserves the space before you get your reservation in, then you are out of luck. Therefore, always reserve ahead. If you get to the campground and there is a space you would rather change to, then you can ask at the park entrance to change your reserved space, if the other spot has not been reserved for someone else.
Land of 10,000 Lakes
2016 Forester MBS 2401R