welcome to UCS and the forum.
Just as an addendum: you don’t need to use the NetBIOS name for joining computers. In fact, the preferred method is using the fully-qualified domain name (e.g.
internal.linet-services.de instead of our NetBIOS name
internal). You can use that for authentication, too:
email@example.com instead of
internal\administrator. In fact, sometimes using the FQDN will work whereas using the NetBIOS name won’t (I’ve observed that with a handful of PCs/installations over the years).
The share itself is created automatically, too, but you have to configure each user to actually map a network drive automatically. This can be done in multiple ways: either via the user settings in the UMC (Univention Management Console, the web-based management GUI), via a netlogon script that executes
net use …, via a group policy…