Best practice to share calendars

Now that I have walked some steps in a dummy config I have some questions that were not answered in the docs so far.
At the moment I want to work with calendars only.
The scenario is 2 Outlook calendars and 2 (or more) mobile phone calendars - 2 users at the moment.
I assume each user needs a nextcloud user set up!?
Then he will sync his Outlook calendar and his mobile calendar through his nextcloud user.
Is this correct?

What’s the next step to set up a common or group calendar?
I noticed, a user can set up multiple calendars but what’s the state of the art procedure to share one calendar?
I could connect calendars of both users via the same nextcloud account but I figure this is not the way it should be.

Yes. Or at least that is the way I would do it.

For sharing, just create a calendar in one of the two accounts, share it with the other one and grant the other user the necessary rights (read or read/write).

Or create another user (a system user you can call it) and that user shares the calendars to both users. What fit’s you best in your situation.

OK, I will see how it works.
Yesterday I pushed the SD install to an SSD and I had not time for testing this.
I will keep you posted.

I followed also this approach. Is there any possibility to prevent this “system user” to logon? Unfortunately deactivating the user would also deactive the calendar.