Sharing Questions

I’m running Nextcloud 12.0.5 and was a little confused by the sharing feature.

If I add an email address in the sharing field how do they login and access the share? Does that happen only if I click the “Share Link” checkbox? I feel like I myst be missing something here?

A link is send to the email adress you entered. Its basically a public link functionality, but send to the person you named.

Mine doesnt email to them. Is it supposed to happen automatically?

Yes if you configured the mail sending option correctly. You can share a public link to any address you want, but you can also share a link to another user of your setup or even with other Nextcloud setups via federated sharing (address is a bit similar to mails: user@other.nextcloud.example.org).