To create a series of events first set up a template for your event. While creating it if you want to create your series at the same time as creating the template, then you can create a bunch of events via the Repeat tab.
But the 'repeat settings' (eg ever Monday for 6 weeks) do not get saved in the template (trick 1)
If later you want to create a single event based on the template then you click on the 'Create' on the ui showing all the Event Templates but this does not give you the ability to make multiples.
If you want to do that, eg to add a series for Tuesdays then you need to click Edit for the relevant template and go back to the Repeat tab of the Event Template, and fire them off from that screen.
I think what tripped up our user was having created the Monday series she could not figure that to go back and create the Tuesday series she needed to 'Edit' the template to get to the Repeat feature