First, go to the Events menu at the top left of your screen and then click Add Event.
Under the 'Add Event' page title, click on "Or, copy an event you have run before."
Find the event you have run before in the Event to Copy search bar (the event must be public). Then, name your new event in the Name of New Event bar.
Your new event will have the same Event and Setup details as the previous event (with updated dates and mailing lists). Make sure to update the Location, Tags, or Coordinators on the Event page if those details have changed. Also make sure to update Divisions, Pricing, Data Collection, and Waivers on the Setup page if those differ from the original event.
Note: Event Blurb and Price Point Information will not be copied over as those are generally highly specific to the original event.