Welcome to the comunity sdgenxr,
To log in to the LinuxMCE Admin, basically you have to use the name that you give on the wizard for one of the user(I think the first one you entered). usually the user and pass are the same
if you use
the user will be sdgenxr and the pass sdgenxr
I don't know what will happened if you use a name and last name like jhon smith.
Just in case probably you already know you have to go to http://192.168.80.1/
(this is the default url for admin)
unfortunately, your second concern is related with the admin site, some times not all media is recognized by the system (at least in my case) I had to go to the admin Files & Media | Media Files Sync and look for the drive that my media was located(on the left side other - name of your HD) and then synchronize. When you get there you'll see it is very straightforward. I do not know how NTFS get along with LMCE.
do not worry about the trouble that it seem at the beginning... it will continue for a long time.