I feel a lot of advice here is trying to push the learning envelope without considering fun & the learning experience. This is for an 8 yr old, and I'm seeing suggestions that would seriously challenge high schoolers, college students, and even some software engineers in industry I've encountered.

For the software aspects of programming, I would suggest looking at programming(-esque) games and web browser programming environments. Here's a solid short list, vaguely sorted from "proramming-esque" to "actual programming":

• https://upperstory.com/turingtumble/ - A physical algorithmic marble and lever puzzle "board game". Great (and designed for?) for kids. Not programming.
• Factorio - A factory-building game that "feels" a lot like software development. Not programming.
• Opus Magnum - mechanical puzzle game by Zachtronics, build algorithmic "molecule-building machines". Not programming.
• - varies from "not-programming" to "contains programming". Can get pretty difficult sometimes.
• Human Resource Machine - Programming puzzle game using assembly-like language. Later stages are challenging.
• 7 Billion Humans - "sequel" to Human Resource Machine, more featureful language, has concurrency and randomness. Later stages are challenging.
• https://www.hedycode.com/ - An innovative learning programming lang and "levels" method that makes Scratch primitive by comparison. Has free online lesson plan & environment. Hedy level 18 is vanilla Python.
• https://www.codecademy.com/ - you said you're using this already

Suggestions to go physical tinkering with electronics is good, but I'm unable to make good suggestions there.

A real computer and coding environment/shell could be good for system admin skills, but the learning curve is steep. You'll also have to be okay with letting him accidentally brick the computer (best way to learn!).