You have two options to add more events to a course:
Within the context of a course, you can create multiple different events. E.g Workshop 1, 2, and 3. Events are compulsory for course completion, so by creating three workshops, you are requiring each event to be enrolled and completed.
You can have a single event (Workshop 1), but with multiple dates for that event, based on location and date create with the context of 1 event.
Add more Dates to an Event
Access Course editing page.
Select on Event card to edit the event.
Select Add Date to add new date to the event or duplicate on the edit event form.
Now update event date and/or location.
Also if you enter Multiple dates your learners will be able to select any of those dates.
Additional Info:
Deleting Events