Looking at the table of contents (Japanese / English) , I feel like Linear Algebra might be a good starting point, since there’s an early chapter devoted to teaching fundamentals of mathematics like sets and functions, which might be useful in general.
For more CS resources, here are two I found:
Progate - a website for learning to code, the first 18 lessons are available for free. I feel like this might be suitable for the “short online resources” section if we only tackle a few lessons, or we could go through the whole course.
Intro to CS MOOC - this one is from edx and more of a longer resource (it says 4 weeks on the website but I feel like it would be better to take our time, maybe 8-12 weeks?), but maybe not a beginner resource (or maybe I’m just afraid of having to deal with my subpar listening skills )
Sorry for not using the template but I’m in a bit of a hurry, I can use the proper format in a later post