MIT Scratch seems to work well: https://scratch.mit.edu Works well on an iPad, even better on the desktop
I'd just get a breadboard kit or something. Sure, sites like replit.com exist for ephemeral coding environments, but learning to write code on an iPad is an exercise in frustration, not programming.
MIT Scratch seems to work well: https://scratch.mit.edu Works well on an iPad, even better on the desktop