if you can get into the system by using root as a login name (plus you should enter a password if you added one during install), does it open the graphic window?
Cos if it does, then things are straight forward.
You should have an icon at the bottom? of the screen that looks a little like a tv screen, and when you click it, it should open a window with a prompt that look something like root@Cipherfx # (the # bit's important as it tells you that youre in a root terminal).
anyway, if you got in ok and started the terminal, you have to put in the
command, but you will need to make it look somthing like this
# useradd -m -G users,wheel,audio -s /bin/bash Cipherfx
I cant break the command down completely, I don't know enough but that's what I had to use to add a user (taken from gentoo's installation handbook). The users,wheel,audio bit is to do with the groups that you'll need to be in as a user i.e. the users group to do the stuff that users can do, the wheel group for both wheel mice (I think) but especially so that you can be in a user account open a terminal and then issue an "su" command so you can become root and install or manage stuff, and audio as most sound related stuff needs that.
If you get that done, you'd then need to allocate a password to the user account, you do that with the
command, and when it asks you put in whatever you want as a password, you'll have to repeat it when asked.
If you didnt apply a root password when you installed, then you'll really need to apply one, thats done with just the
command (note that you don't need to say passwd root, just passwd).
Failing all that, just re-install the distro over the top of what you've already got, but make sure to allocate root password and both a username and a user password.
hope that helps a little