https://www.udemy.com/course/applied-math-for-ml

First step: where do I buy one from?

A course about online course design.

An online course should be different from the classroom experience. It should be heavily asynchronous.

Teachers and students should come together live only for discussions. For example, there is no point in having students watching a video while being all together in the virtual class. Instead, upload the links to the video beforehand, and announce the topics for the debate that will be conducted live.