This is a really basic campground option right on the Homestake Reservoir road. It has space for one tent for sure, and several more tents if you aren't picky about smooth and level ground under you. You could definitely fit an RV or trailer in the space as well.
When I visited there were 2 fire rings. Firewood is not for sale nearby and the forest doesn't have much, so you should bring your own.
If there is a lot of traffic you'll know it since this camping spot is right next to the road.
If this location is full there are more spots as you head up the road.
My family of 4 had a great time at Big B's. Our only complaint was that it was quite hot (topped out near 100 degrees). The prepared food and cider were tasty, we got some fresh fruit and processed items to bring along with us (the peaches were amazing!). Our kids aged 8 and 11 absolutely loved the big tree swings.
We camped by the pond in a tent. You're pretty close to the next tent out there. The orchard and field areas were wide open and if we needed more privacy we could have moved to an orchard location. The ground is fairly uneven in most of the camping spots we saw.
The drawback with the heat was that the pond wasn't really the kind of place you'd want to swim and the river is fenced off. If we could have had a way to swim that would have made the heat more bearable.
A suggestion: Bring quarters for the showers, which are clean and work well, but you need quarters for them. The shop is only open during business hours of ~9 or 10 in the morning until 8 PM at night. They also have a few hoses for drinking water if you need it. There are no hookups for electronics or sewer disposal.
They have 2 "tiny house" style units that were just built and 2 platforms with large canvas tents in progress that seem like wonderful options if you want a low hassle and more comfortable/bigger tent experience.