Yes, I did just duplicate the default and reconfigured the directories and names.
Yes, I am using Zentyal (for the first time), don't think I'm using Zentyal for virtual host management but then again I don't know what I'm doing.
I'll redo the server and see if the http://<ip>/<user> works, I didn't try that earlier, I just knew that the root directory was not a folder with subfolders "user1", "user2" and so on.
Can you tell me what to do after I install Zentyal?