Take it to a local hobby shop that sells and services RC stuff. They can give you tips on how to pair it with a transmitter.
You can use that body... the shop can give you tips on how to paint it... on the inside if you didn't already know... that's a polycarbonate body and it's not as fragile as it looks.
Running it in sand, loose dirt, or mud makes for nasty cleanup and maintenance (and speeds up wear and tear)... hard dirt or clay is better.
Or you can run it on asphalt (on different, more suitable tires) in an abandoned strip mall parking lot. Have you ever driven an RC car?
YT has a lot of videos on the Tamiya 959:
https://www.youtube.com/results?search_query=tamiya+959+rc