RE: Suggestions for first kit for 13 year old
I did a Kadet LT-40 kit with a 10 year old that I had met at the local field about a decade ago. We worked on his model every Sunday afternoon for a couple months until it was ready to go flying, then our Sunday's changed to flying sessions. We followed that model up with a 4-Star 40, which was a faster build the second time around. The main point is to do as little of the building as possible, but talk the kid though it with a simple demostations where necessary. I had a huge shop at that time, so I worked on building other models while he worked on his. Learning to read plans, cut wood, sand parts, cover, and install the gear are major sticking points for beginners, but easy to learn with a guide.
We flew a couple hundred flights together before work moved me across the country. Last I heard, he was studing engineering.