After my first ever RV purchase and 3 week camp out, I've learned a lil sumthin about having options for power hookup.
I encountered- 15A, 30A and 50A hookup at different CG's.
I have a 50A surge protector
50 in 50 out and needed to get all kind of adapters to fit.
30A male > 50 female dog bone
50A Male to 30A Female to connect to the trailer Furrion cable.
15A male to 30A female
And having a 25' and/or 50' 120v 15A OUTDOOR extension cord never hurts.
Hope this helps just 1 person.