[Xavdidtheshadow]

As another commenter notes, programming with a specific goal in mind is a good way to start. People can't sit down and learn "math", it's too broad a subject. Instead, you sit down and learn how to do a specific task (solve for x in an equation) and build from there. A lot of younger engineers today learned things like HTML/CSS/JS to customize/exploit Neopets and Myspace. It's not that they were interested in programming, they just wanted a result and figured out how to make it happen.

So to that end, I'd probably start with a project-oriented book, or give them tasks that require programming to solve (e.g. tell me the distribution of words in this Shakespeare play. What are the most common ones?).

Editor wise, VSCode is great, but may be too many bells and whistles. Sublime Text may be a better place to start, since it'll do highlighting, formatting, etc without being overwhelming.

Language wise, Python, JS, and Ruby all have ample beginner resources. Depending on what else they're into, JS is probably the most widely useful (since it's on most web pages and the sandbox is built right into the browser).

Good luck! Let us know how it goes!