There are various codes and standards that will have to be complied with.
NFPA 1194 for example covers roadway & site constr., plumbing, sewer & water, toilet facilities, fire protection, dump stations, etc. NEC art. 551 covers electrical for RV sites. There will be other various codes, regulations and local bylaws covering things like environmental and buildings. You will need to hire consultants and engineers for some of the work. A prime consultant is probably best.
Features and facilities you provide will depend on your target market such as full-timers, weekenders, families with young kids, some permanent sites, tenters, group sites, rental cabins, permanent TT or FW rental units, "upscale" RV-ers, etc. Knowing the local competition including their strengths and weaknesses is very important too.
A few ideas: 50 amp RVs are common nowadays - build above the min. NEC requirements of 20% pedestals for an RV park. A few CGs store FWs & TTs year round, owners can book a visit and the CG puts the RV on a site so owners can visit in a car - provide a storage section. Provide some pull-through sites for long MHs plus toad. Provide decent space between sites. Make sites level - no close enough!
If OP has never owned an RV or been around to lots of different CGs in different places, it'll be hard to know things that will contribute to the success or failure of a CG. Then, *if* you can make it to opening day, good management, good staff and good maintenance can have a big impact.
