VS Code with C#. Why: VS Code is the editor and no matter what comes next in his choices, even random non CS stuff, VS Code will be good. Maybe start with a notebook and not a program in the first days.
Why C#: it is the most versatile platform. You can create apps, web stuff, servers, desktop apps, machine learning, console apps, etc. It is statically typed (which is important for the youth to understand what he is doing), has excellent intellisense and beginner friendliness was a focus in the last year (a one liner is nowadays a valid c# program). .NET as base platform allows also F# for a switch to the purity (do not make me comment on that), can run on Linux/macos (if this is important to you) and most important: is not Python which everyone else is doing. Python is the new boring Java.
Why C#: it is the most versatile platform. You can create apps, web stuff, servers, desktop apps, machine learning, console apps, etc. It is statically typed (which is important for the youth to understand what he is doing), has excellent intellisense and beginner friendliness was a focus in the last year (a one liner is nowadays a valid c# program). .NET as base platform allows also F# for a switch to the purity (do not make me comment on that), can run on Linux/macos (if this is important to you) and most important: is not Python which everyone else is doing. Python is the new boring Java.