Hi,
Thanks for the interest in our plugins. I can answer your questions.
Community Events Plugin requires the core version of the Events Calendar found for free on WordPress.org: https://wordpress.org/plugins/the-events-calendar/
The core version enables event creation from the admin, while Community Events creates events from the front end.
Both those events are stored in the same place in the admin.
Check out our New User Primer for how Community Events works:
New User Primer: Community Events
You can see the same New User Primer for the core version as well:
New User Primer: The Events Calendar and Events Calendar Pro
Let me know if you have any follow up questions.
Thanks