You will need either a self contained bathroom (rv) or portable toilet. There are no bathrooms at upper madera or water. As well you can't bury your waste at this location. At the lower madera sites they have a pit toilet, but you can't really walk to them from the upper campsites. As for showers maybe pay at one of rv parks in town. There is a section on the state park website that talks about the toilet options. They used to rent/sell a 5 gallon bucket and seat with bags but the store was closed do to covid so come prepared.

There is a pit toilet in the Lower Madera Campground, nothing in Upper. You can get water at the Visitor's Center. I'd suggest asking at the visitor's center where you might find pay showers, possibly at the resort in Lajitas. We stayed 13 days and loved it here!

Update! There is now a pit toilet at upper Madura. It's one of the newer toilets we used and gets a decent breeze through it to keep the smells down. Showers are only at the Ranger Station at the interior, which is several miles of dirt road away.