Delegates should be used when a person will need to receive/process meeting requests on someone’s behalf. For example, a manager wants their assistant to process all meeting requests on their behalf. When using Delegates, limit the number of delegates to one or two people. A manager and delegate should not be configured as delegates for each other - only one should be a delegate. To work as a delegate, another Microsoft 365 user needs to give you permission.
If you would just like to share your Outlook Calendar, Tasks, Inbox, Contacts, Notes, or Journal with other Microsoft 365 users so they can see your availability, you should use "folder permissions" instead of Delegates. With Folder Permissions you can give different permissions based on your needs.
Note: As the Organizer of a meeting you are a required attendee and cannot remove yourself. However, to mark your time as free, right-click on the meeting and set Show Time As = Free.
Note Regarding Multiple Delegates Handling Meeting Related Messages - It is not recommend to have more than one Delegate. However, that being said, if a person has more than one Delegate, we recommend that only one of the Delegates handles the meeting related messages. The other Delegate may want to move the meeting related messages to a separate folder or just delete them. If one Delegate accepts the meeting request and the other Delegate deletes the meeting request, the meeting WILL remain on the primary user's calendar.
See Best Practices for Microsoft 365 Calendar Users for additional information.