Not the parent, but I did an undergrad maths/physics degree some time back and found https://www.coursera.org/learn/machine-learning to be good as an introduction, unfortunately a new job [unrelated] has prevented my finishing the course but I hope to pick it up again later in the Winter.

I would be interested in thoughts from anyone with ML experience who has reviewed said course's materials?

I've always had way too much math under my belt which helps a lot and have taught myself a lot of genuine computer science out of personal interest. I actually did Andrew Ng's Coursera machine learning class all the way through as a first introduction to that field before realizing it wasn't so mysterious and was just the application of a lot of math I already knew, then ran through a bunch of tensor flow tutorials when that first came out and the like. Then just experimented on my own. I have a knack for data though.

Formally from school, I've only had 3 semesters of scientific programming in Fortran and a shitload of math. That and years and years of building models and massaging data in Excel.

Mostly I'm just really used to learning a new API/tool and applying it to new things.

A lot of the ML stuff hasn't been fancy ML, just basic things but applied in really clever and novel ways.

Study stats and convex optimization. If you understand logistic regression and MLE, you're mostly there.