Hey Melanie,
First off, thanks for purchasing WooCommerce Tickets! So glad you did and I hope you’re enjoying it so far. 🙂
Good question about Community Events and Community Tickets. It would be possible for users to edit and add tickets retroactively for events that they have created. However, this would not be the case for the events that are currently on your site since they were not created through Community Events. In other words, the events on your site now would need to be edited by you and any events created by users in Community Events moving forward will allow those users to add tickets to those events later when Community Tickets is activated.
Does this help clarify things a bit? Please let me know!
Cheers,
Geoff