You can reserve a specific site at only a few Texas state parks. Most parks you can only reserve a type of spot, and will be assigned a spot upon your arrival. Early in the day arrival gives you a better selection of spots.
I have no idea what type rig you have, so don't know if all the sites will be suitable.
Dinosaur Valley SP - 30amp only - nice small CG on a good loop. Most sites are shady - no window for satellite coverage, little over the air TV. We love taking the grandkids to the park, much to do for them floating around the loop of the river, hiking, night programs in the summer. We like site #24. If you want some sun and be close to the restrooms #44 is good. If your rig is tall, you might have to stay in the 40s area. Watch for overhanding trees.
After Dinosaur Valley - go west to Stephenville and south on US-281 to Burnett, then west on TX-21 to Inks Lake SP. A jewel of the SP system in our opinion. We prefer sites in the 260 - 275 area. Great restroom. Access to water. Plenty of room between most sites. Inks Lake is close enough to visit Enchanted Rock SNA and Longhorn Caverns for a day trip. Enchanted Rock is a must see, but they don't allow RVs in the CG.
South of San Antonio Choke Canyon SP is a nice stop. We like any waterside spot.
Look at Mustang Island SP on Google Maps/ Bing Maps. It's is a parking lot with utilities at the back of the spot. But location, location, location. We like it, though Nueces County has nice parks at Padre Balli and Port Aransas. We prefer as far south/west as possible because the ocean water is usually cleaner. It's not tropical - see coral 40 feet deep - clear. It's not even Florida clear,, just cleaner away from the ship channel at Port Aransas.
The site really doesn't matter. You can't stay with a clear view of the water except at the city of Port Aransas beach area. The protective berm is present. But it's just a short walk to the water.
Full-Time 2014 - ????
โNot all who wander are lost.โ
"You were supposed to turn back at the last street."
2012 Ram 2500 Mega Cab
2014 Flagstaff 832IKBS TT