1) Make him come up with the projects to do. Use brainstorming techniques. Only help by guiding, not by telling him to do specific things

2) Build your similar own projects as well

3) Try with electronics. For that age group I have had good succes with MicroPython on ESP32’s + various sensors/actuators. The first thing I do is connect an LED strip with RGB LED’s and let them play with that.

4) Find him peers with the same interest. In that age peers are better partners. You can still help facilitate a bit, but the best would be to find a Coding club.