Try typing in startx at the prompt....I had the same problem when I briefly tried Slackware and I believe this is the same solution I used. Oh, a little hint, in that situation you could have hit kd<TAB> (as in the tab button) (I think you have to hit tab twice, I just do it without thinking about it so I can't remember right now)
and it will show all possible completions
Anyways, as a newbie have you thought about something along the lines of Mandrake/Fedora/SuSE? I personally use Fedora and even my mom and little brother use it too and they don't have a problem (I do all the admin tasks tho). And, most of the admin tasks are done through graphical windows in your main menu, whereas I have heard (could be wrong) that Slackware involves a lot of admin work through the command line.
Anyways, just some advice. If you are the type of person that likes to jump right into the deep end and learn that way, Slackware is probably a good choice for you tho. Anyways, hope I've been of some help.