When I was a teenager, I built and launched model rockets.
Most of the models I built were pre-designed kits from the model rocket company Estes. Some were designs of my own. Some were very simple. Some were quite elaborate.
Usually, I used a stiff paper tube for the body and a cone of light balsa wood for the nose cone and fins. The parachutes were thin nylon sheets and strings.
I didn't risk making my own motors, just bought them from Estes.
One model that was easy to build was a ten centimeter paper tube with a two centimeter nose cone and three short fins. It was light enough that it didn't need or use a parachute.
A more elaborate one was a model of the space shuttle. I built it for a physics class at high school. We used our physics to check how high it actually flew. But I was too impatient to get the right motor, and my rocket crashed. I was disappointed, of course, but it was a good experience.
You have to be careful when you launch rockets because they can be dangerous.
I learned a lot about physics and responsibility from building model rockets. And it was fun.