Hey there!
Interesting question. You’re right that tickets can be imported in the CSV Importer and attached to an event. I think where this breaks down aa bit (at least in this specific case) is that recurring events do not currently support tickets — so, in other words, importing the ticket to a single event is the only possibility art the moment.
That said, you can find the event ID in WordPress itself. One way I do it is to hover over the event title in the admin area and see what ID number is in the URL at the bottom of the screen (screenshot).
Does this help answer your question? Please let me know. 🙂
Cheers!
Geoff