Try the Caravan Club of SA web page for your nearest branch.
At the top of the page is a link to "Clubs".
Click & scroll down. You will find a list of clubs in all provinces.
Welcome to the forum - I'm sure you are going to get lots of info and advice here
Allthough I stay in Polokwane, old Grumpy's (Caravette 5) is parked in a store in Potties (Mokopane)
I dont belong to a club and mostly camp in the Naboomspruit (Moeggepong), Warmbarths(Bela se Bela) area.
Stil looking for a nice resort/camping area in Magoebaskloof. There is one place in the kloof but they only have +/- 4 stands. They cater more for Chalets. The other is only accessable with a 4X4 Car & Van.
The other one is on the Tzaneen Dam, but I will not stay there even if they pay me. (Entrance next to Merensky School)
If you find any nice places please let me know.