To delete an event, please go to your Events page and select the event that you'd like to delete.
Within your event details, towards the bottom, you'll see two options - "Delete Event" and "Save Changes" - simply click "Delete Event" to remove this event from your page.
Note: If you already have RSVPs collected for an event, you will not see the "Delete Event" option. You will need to head over to Track RSVPs here and update the RSVP responses to "No Response." Then you will be able to delete the event.