The easiest way to find RV camping resorts is to use the online search features at the websites for KOA and the Good Sam Club. Both offer memberships, but non-members can use the search features and make online reservations. Membership does offer discounted camping rates in either case.
KOA, which stands for Kampgrounds of America, lists campgrounds in the United States and Canada. Click on Find a KOA, then enter a city or state to find all the listings in that area. Narrow the search by putting in a city, state and ZIP code, or province and postal code for Canada. For example, if you enter a location in California, all the KOA sites show up as red dots on the state map.
Clicking on a dot pulls up all the information on that location, plus a link to that campground. Choosing Pismo Beach pulls up amenities, the exact location and the type of RV sites available. All campgrounds listed are members of KOA. The firm has strict standards, and many of their campgrounds do fall in the resort category.
Good Sam's search works much the same. The main difference is that Good Sam pulls up information on all RV sites in an area, not just those that are members of Good Sam. Search by state, or use city or ZIP code, postal code for Canada, or a park name. Select if you want only Good Sam parks listed. Using Pismo Beach, the site pulls up one Good Sam park and several others. Then it's just a matter of reviewing the choices.