There are three ways to edit an event on your site.
On your calendar page put your mouse on the event you want to edit then click the event event button.
This will take you directly to the edit screen for this event.
At the top of the calendar or event list click the event list admin button. This will take you to the list of all events in the admin area.
In the admin area go to events > all events. This will take you to the list of all events in the admin area.
In the admin area there may be several pages of events. The circle in the image below shows there are three pages of events in this example. So if you don't see your event on the first page check the other pages or better yet use the search option to find it quickly.
Once you see the event you want to edit click on the title of the event. That will open the edit screen for the event.