Plans for an ARIA/SR-focused course?

I saw that there was an accessibility course so I pounced on the opportunity to create an account. While it does provide a valuable understanding of people's circumstances and a very 101 overview of design for accessibility, it doesn't provide more insight into ARIA roles, tags, and use cases.

I've been going bonkers trying to find a reasonable tutorial on designing for screen readers, but most information I find tends to be a bit unclear. From what I gather, most use the rotor function of a screen reader and navigate through headings to find relevant content. Really, I suppose it would take a day or two for me to play around to discover how to code to create the best organization within the rotor, but I was hoping to get a cohesive jump-start.

At any rate, this isn't so much a question as much as it is a suggestion -- unless there's a course that addresses this.