Although you can camp just about anywhere in Pisgah National Forest, there are specific sites near the trailhead to Sam Knob. This area is known as Black Balsam. There are no RV sites, and you have to hike about a hundred yards or less to the sites, unless you camp on the bald. The sites had lots of roots, so it was difficult to find a level site without roots all over the area. With that said, it is a good place to camp, and it is just a short walk to the pit toilet, which is also at the trailhead. There are fire pits, but there are no lantern hangers or tent pads. Expect to hear lots of cars and people during the busy months about 200 feet away. Because of that, a better place to stay is at the top of Sam Knob, which you can do. That was a better choice for me since I try to stay away from crowds as much as I can. However, you cannot clear or make a new spot; you have to“find” a spot in which you do not disturb the area. You will need a freestanding tent since you will probably be pitching it on solid rock.
The biggest problem with staying on the knob is the weather. Unfortunately, it poured rain and was windy when I was there. I expected it to be windy, but mixed with the rain, it made it unpleasant. Sam Knob is a heather bald, so that gives you a little privacy. However, expect a hikers to end up there since it is a hiking destination and the views are great.
Overall, it is a good place to camp, but there will be people close by no matter where you pitch your tent, whether it is a hundred yards from the parking lot or up on top of Sam Knob.