You are going to be limited but you should be able to find sites that will work if you research the campgrounds carefully. We fulltime and I (Karen) use a wheelchair. We have found that many campgrounds do not have accessible sites and if they do the sites often do not fit the criteria for handicapped access. Sometimes the fact that the restrooms are next door is the only reason they are considered accessible which is not a priority for us since I use our RV bathroom exclusively. There isn't a standard for accessibility in campgrounds and as far as I know there are no federal requirements to provide accessibility unless the campground is undergoing a major rebuild.
The best accessible campsites have long, wide, flat paved parking pads with the pavement extending under the table and around the fire ring. These are rare but they are out there. I write about accessibility at every campground that we visit but we tend to boondock and stay in smaller campgrounds which may not work well for you. I can give you information about some that are so good that they've stuck in my mind if you're interested or you can just scan through all of my blog posts where I mention a campground -
http://rollinginarv-wheelchairtraveling.blogspot.com/search/label/CAMPGROUNDS Please feel free to PM me or contact me through my blog if you're curious about anything.