After you've installed and configured Scoop (to an extent, at least), you'll want to try it out. Make sure MySQL and Apache are all running, then connect to the appropriate address, depending on how you configured it. For instance, if you configured for a location-based install, then connect to ``http://www.mysite.com/<path>/'', or if you did virtual host, then ``http://<host>.mysite.com/''. You should get the front page, welcoming you to Scoop. At this point, you can go ahead and log in. The username is ``scoop'' and the password is whatever you set with the installer. If you did it by hand, then the password is ``scoop''. Go ahead and poke around some. If you get ``Permission Denied'' when you try to do any admin functions, then read the Scoop FAQ. Most likely, it's a cookie problem, and the solution is in the FAQ.
The default user is a Superuser, so he can do anything on the site. However, you probably don't want to run your site under the name ``scoop''. So log out and use the ``Make Account'' link (right about the form where you logged in) to create an account, just like a normal user would. When you get the email, go ahead and confirm it. Now you can log back in as ``scoop'' and use the form at the bottom of ``Admin Tools'' to change the user. Enter the username that you just created and click ``prefs''. At the top, change ``User group'' from ``Users'' to ``Superuser'', then go to the bottom and enter a new password in both fields (unless you like the random pass you were mailed, in which case you could keep it). Click ``Save Preferences'', and your user will become a Superuser.
It's also a good idea to disable the ``scoop'' account. To do this, enter ``scoop'' into the ``Admin Tools'' form and click ``prefs'', as before. Now change the ``User Group'' from ``Superuser'' to ``Anonymous'', and if you didn't set a password with the installer, then change the password too. Now click ``Save Preferences'', and logout (since your user is now the same as someone not logged in). Now you can login with your new user and really start exploring Scoop.