Thirteen is a great age to start. I took my first aerobatic flight when I was 13. We had a small charity airshow every year and that year they had a big name team (anyone remember The French Connection team?) doing a demo in a new aerobatic plane. They announced that they were going to be giving aerobatic rides the following Monday. I talked my parents into letting me skip school that day and bugged my mom for a ride to the airport.
The guy didn't know what to think when this kid walks in and plops $50 on the counter and demanded a ride (the rides were actually meant for prospective buyers of the airplanes, not kids looking for a thrill). He had to go out and talk to my mom first but finally he handed me a parachute and barf bag and took me up.
Didn't need the bag. First he rolled inverted and asked me if I felt OK. I felt great. Told him to do more. We did everything he usually did on demo rides and a few more. When we were done we sat and talked for three hours about flying until my mom came and dragged me away.
If you want to find a flight school just go to a nearby airport and ask them if there are any good schools around. I did my training at an airport about 12 miles from where I lived.
Some years ago an 11 year old flew around the world. His dad was a flight instructor and of course he couldn't be a pilot at that age but he handled everything on the whole flight just as if he were.
Go for it if you think you'll like it.