well if you entered your username and password, you are loggen in.
i suppose you mean you want to get to the gui, instead of command line
xf86config is run to configure you video hardware.
startx is used to actually run the gui.
you need to be a little more specific. why didnt they work? waht errors did you get?
just a side note, you might want to think about being a little more descriptive in your title, eg. "cant run gui in mandrake", rather than "mandrake help".