Some camp areas have dump stations, some do not. Usually they are for paid campers only; sometimes they are open to others for a fee.
Some people use a portable "blue tote" to haul their waste to the dump station; some take the whole rig. Your time between dumps will vary depending upon the amount of waste you and your family produce and how large your TT's tanks are.
There are lists of dump stations online.
Sanidumps.com is one. Several years ago I bought a downloadable list from them because I often cannot be online when I travel. I don't know if they still sell that list. Explore their site.
Best wishes for enjoying your new TT!