30a rv box from main panel
As this is at the main it would be fine to have both your neutral and ground on the same buss. an RV “park” doesn’t require an additional grounding electrode NEC 551.75.b
However 1 out of 3 of the counties I work in requires a supplemental ground at the pedestal as this a residential hookup not a park.  

Make sure to have your box 2 feet off the ground or more but not over 6’6”.