Events can be edited/deleted by the event creator or any Confluence administrator.
Limit read/view permissions
You can limit read/view permissions of an event to specific spaces. Only users with access to these spaces will see the event.
Add write/edit permissions
You can add write permissions to an event. To do so, add users or user groups as editors to the event. These event editors have full write/edit permissions for the this event.
Add anonymous permissions
In order to make events visible to anonymous users, the user profiles must be made public (right-hand checkbox) in addition to the general access (left-hand checkbox) in the administration area under Global Permissions -> Anonymous Access.
Without both ticks, anonymous users cannot see any events.