This was how I started with my son, who was also 10. Have him learned Scratch from MIT, learn how logic is constructed in a program Then I got him a couple of Snap Circuit kit. I know you said no kit, but this is just to learn basic circuit and electricity flow. Then we used a Raspberry Pi to learn Python. Once he's comfortable with Python a bit, I set up an environment to program micro controller, specifically the ESP32. I flash Micro Python on there and we started to program some LED string lights. Then control motors with H-Bridges. After that, it's onto robotics and anything we can get our hands on. I repurpose a baseball pitching machine to launch pickleball, with bluetooth connectivity to boot! All with an ESP 32, I can control the speed and rotation of the ball, which the original machine only had one speed and no rotation. It took my son about 2 years to get from zero to building robots. Good luck!