Iv'e created a "Create Event" quick action on Account. The quick action(Created Event) is not visible on the lightning record page. Is it possible to create a record (Event) on Account standard object, having event and account object does not have a relationship.
Whenever you create the quick action of type create a record and related to object Event and Task, It will never come on the Highlight panel in Lightning. It will always come under the activity tab after adding that quick action to Salesforce Mobile and Lightning Experience Actions section of the page layout.
If your activity standard component is not added on the Lightning Page layout, Please add it via following these steps:-
click on setup-> select edit page-> from left side panel, drag the activity component in separate tab->save it and activate it.
Refer this trailhead module to understand more about Actions in Lightning :-
You can create 'Create Event' quick action on Account.
In order to display it in lighting record page, you need to add quick action under "Salesforce Mobile and Lightning Experience Actions"