Am not aware of a campground in Gastonia but there are 3 nearby that I know of:
Kings Mountain SC State Park has water/electric and a dump station. It's wooded and the sites and roads are gravel. I have camped there and would again.
Ebenezer County Park in Rock Hill SC is on Lake Wylie. S/W/E and also gravel roads and sites. We have visited this park and planned to spend a few days there but haven't gotten around to it.
Trailer life lists Cross Country Campground in Denver,NC. I've passed by but never been inside the campground. They have lots of permanent campers and TL says the available campsites are only 25' wide...but it is on Lake Norman.
All of these are within an hour's drive of Gastonia.
I hope this helps.
King of the Road 5th Wheel