Ride a horse very fast in an unpopulated area

I’d love to ride a horse out in the open prairie, really fast. I love animals, I have been riding once or twice, but not ‘really’ riding. I was on the back of a sad looking pony at an amusement park when I was 5, and a few times later. Then, last year, I went on a rugged trail with a group of campers on horses! I got to ride on the back of a horse, and it was so fun, I got to control where the horse went and stuff. I would be so happy to ride on the back of a galloping horse in a big open place!