ANSWER: Using the textbook I would probably work through the chapters once fairly quickly to get a feel for the content and you’ll naturally gravitate to the areas you want to work on most, then on a second pass through you can go into more time and more detail on different areas.
In a perfect world you would pass through the course maybe once every 6 months to see if it sparks any ideas you can use – plus always ask answer questions throughout.
This should work around your schedule but still allow you to have a big impact quickly.