I'm in exactly the same boat, and doing very similar to you. My son is 11 and daughter 8. Both do Code.org and/or Scratch fairly regularly. Son wants to get into modding Minecraft, but honestly I'm a little annoyed with how shady and complicated that process is. Or maybe I'm just too old to "get it". I don't discourage him from it, but haven't been able to teach him that as much.

Son also recently bought with his own money a Arduino starter kid off amazon. You can get an arduino, LCD, servo, LEDs, etc. for 30-40$. We've taken it a step at a time and go through various concepts, etc. For example, I talked to him about 'rubber duck debugging' (ie explain the program to a rubber duck or plus toy line by line), semicolons, code blocks, etc. This has been great for learning real C and tinkering with electronics.

I plan to start them on basic web stuff on glitch.me sometime. That should let them build simple websites etc. for free.