Hi,
Thanks for the interest in our plugins.
I can help out here.
EDD and all our ticketing plugins create the tickets per event and actually tickets can only be created in the event itself.
So if you are using tickets only in your events you can create them there.
For the other events you would not need to create tickets then and none would show, but you could still put a link in the Event to buy tickets elsewhere.
Before buying the plugin I encourage you to look at the New User Primer to see how everything is setup:
https://theeventscalendar.com/knowledgebase/new-user-primer-edd-tickets/
Let me know if you have any follow up questions.
Thanks