I’m dealing with this right now too.
My advise is to ditch the PDFs where possible, and go with HTML documents. They are far easier to make accessible. The down side is you can’t easily pass them around in a self contained way that isn’t a bit wonky compared to a PDF or DOCX. But if you just link to them in a course, or otherwise expect students to just access them in a browser, HTML pages can work well.
PDFs have always been a nightmare, and the new accessibility rules are making thousands of people in education finally realize that.
The thing is, you need to make proper PDFs with properly structured content with proper metadata for screen readers to be able to access the content in the PDF in a logical and sane way. This is what the OP is tasked to do, and why they are looking for help. So I’m not sure what you mean by “try just using screen readers.”