Depends on his age really - there aren't any books I'm aware of that are focussed on "children": they all assume you are at least a young adult with a reasonable attention span and "mental focus"
Trouble is they are generally expensive, so I'd start by checking my local library - most can access books from the entire country and may have some goodies. Look for MS Press, Addison Wesley, and Wrox, but avoid anything with "In XX days!", "For dummies" or multiple exclamation marks in the title.
There are free ones, such as The Yellow Book (
https://www.robmiles.com/c-yellow-book[
^]) but they don't cover as much and aren't quite so focussed one "from first principles" education as some of the (much thicker) paid or ones.
The good news is that the IDE is free:
Visual Studio 2022 Community Edition – Download Latest Free Version[
^] and seriously good!