Hey Juliw, you are most likely fine. When a campsite says it has a 50/30 amp electrical hookup, that usually means it provides both a 50-amp outlet and a 30-amp outlet on the same pedestal. It’s very common.
That said, it’s a good idea to carry a 50-to-30 amp adapter, also called a “dogbone adapter”. These let you plug your 30-amp camper into a 50-amp outlet if, for some reason, the 30-amp one is damaged or unavailable.
Enjoy your trip!