For my 9-year-old boy, I picked QB64 [1] and things are going very well. The experience is identical to old QBasic, but with a saner language that encourages to declare the type of variables.
At the moment we are following [2], which seems perfect for a child of that age.
[1] https://github.com/QB64Official/qb64 is the repo to follow: after the dramatic split of the dev community happened in 2022, the older one is not used anymore.
I did not follow the events closely, but it seems that one guy, not particularly involved in the development, took charge of the repo and the website and essentially locked it from all the core developers. The story is told here, very interesting read!
At the moment we are following [2], which seems perfect for a child of that age.
[1] https://github.com/QB64Official/qb64 is the repo to follow: after the dramatic split of the dev community happened in 2022, the older one is not used anymore.
[2] https://www.qb64tutorial.com/