My wife and I rented a class C RV when we first got interested in RVing. Of course we got no experience with towing be we did gain some experience in preparation for a trip, some of the set-up and breakdown process when you’re camping, road limitations like restricted parkway usage, restrictions on using bridges and tunnels, height clearance requirements, thinking ahead before you pull into an area (gas station, fast food restaurant, etc.) to judge if I get in can I get out, cost of traveling (extra for gas and tools can be significant) and other unique aspects of traveling in an RV.
So I would say there is some benefit and useful experience gained by renting a class C even if your long term plan is buying a travel trailer.
