When we lived in town, I wanted to add additional parking for the camper, same as you, but beside the house (back then, the camper had no slides). I checked with the city and they said concrete or asphalt required all kinds of permits and inspections, but gravel could be put down anywhere without any kind of permits, as long as the gravel did not spill over onto the neighbors property.
I put a lot of gravel down, and was able to create a really nice pad for the camper. Then almost 10 years later (same house), I received a notice on my door from the zoning board I was in violation, could not park the camper there.... (yea, after 10 years of parking one there on that gravel and 6 years parking on the grass!). Long story short ... we moved.