You'll sometimes see photos of hoopers with one foot forward. This is not the only way, but it's a good position to start from.
Then you hoop from two spots on the waist: one above the front foot and one above the back foot (more or less). And, as shown in the gif of the little girl in pink (in Bella's post), the legs come into it as well.
I didn't know any of this when I started. The hoop would immediately fall to the floor. I'm usually a quitter when things are difficult. I have no idea why I persisted with hooping. I'm glad I did!
If you do try it, alternate between clockwise and counterclockwise, so your body doesn't become lopsided.