Two families first time renting RVs (6 kids ranging from 9-14). We will be flying in to Salt Lake City the 1st of June. 4 Nights at Grand Tetons, 4 Nights at Yellowstone, and 4 Nights at Glacier National. What are the must do things for each location? What should we avoid? We have already booked campgrounds at GT and YS. We will also have a van for commuting at each location. Thank you for your expertise.