To legally fly a registered aircraft of any kind, including powered parachutes in U.S. civil airspace, the FAA must issue you a pilot's license - technically called a Pilot Certificate, which makes you a certificated airman (their words, not mine).
The highest level is ATP (Airline Transport Pilot) - the boys and girls with those fly the big commercial jets. They know a lot. They have thousands of hours of flying experience. They get to wear pretty blue uniforms. They get paid a lot of money to have fun.
After that is the Commercial ticket. You need at least 250 hours to get one. You need to know a lot. You need to take difficult tests - and you need to pass them.
Then comes the Private license. Only need 40 hours of training. At first, you're dangerous - if you live through the first hundred hours or so, you should be pretty good.
Below that, Recreational license - less training needed, more restrictions on what and where and when you can fly. At first, you're dangerous. After that, you're still dangerous.
And lastly, we have the Sport Pilot license. From reading the above, you get the drift. You only need 12 hours of training. If it wasn't for the very forgiving nature of the powered parachute, you'd be REALLY dangerous. But, use your head, get good instruction, respect the aircraft, get some hours and experience, and pretty soon, you'll have the time of your life! Safely! And you get to take up your girlfriend, boyfriend, relatives, and anybody else you want to impress or scare. And, you're a real pilot!
By the way, the Sport Pilot rating has only been around for a few years. Before that, no real instruction was given. "Rules" was a dirty word. The skies where powered parachutes lived was like the old west. Fun, but scary. Lots of people ended up in the trees, but thanks to max speed of 26 mph and the chute, most walked away in one piece.