When you first create an event, it is automatically saved as a private draft. As a draft, only you and your other admins can see it. It won't be made public until it's published. You can publish your event in the event dashboard. Click on the green 'Publish' button, or the small arrow beside it to see your options.
Completing an event
When your event is finished, it will no longer appear in your Hub for signup. Change the status of the event to 'Completed' when finished.
Closing an event
If you'd like to close applications for an upcoming event, you can change the event status by selecting 'Close Applications'. The event will still be visible in the Hub, but the signup button will say that applications are closed.