When you visit your installation of Moodle, does it look like the front page of http://moodle.org (without the classes and the text in the block on the right)?
If so, login to your course with the Administrator username and password that you created when you installed Moodle, just as you have logged into this site with a name and password.
If you get this far, let us know and we'll lead you to the next step.
p.s. If the page doesn't look like the Moodle.org homepage, what is it that you see?