Deleting the events function leads to deleting all the data permanently and disappearing the Event from the lists under My Events. Therefore, before deleting the whole Event, you can consider cloning the Event as a backup or deactivating the Event as an option. Please kindly see in details of

Deleting the event function cannot be accessed by the Event organizer admin site. However, the EventNook team can help you delete it, and if you wish to do so, you can contact your account manager directly or email hello@eventnook.com.