If you do not have a submitted order attached to an Event then you are able to delete it.
On your Events page it will display an option to "delete" events that do not yet have any orders
To Delete an Event click the "DELETE" button
Then, when prompted to confirm that you want to Delete the Event, select "Yes"
Please know there is not a way to undo this action, so be careful when you opt to Delete an Event from your Dashboard.