Hi Colleen
I hope I'm reading your post correctly, we also have a number of standard courses that we run workshops in at various points in the year. We have one course page and then have multiple seminar activities on that one course page. We just create each workshop as a new event on the course page. I've attached a screenshot of what our course looks like showing the seminars available and just one course tile on the catalogue. We are using Totara version 12.
Hope this is of some help.
Sue