Not sure how far you have got with the installation, but the values below (in the WA_Globals.php file):
// Admin Settings
$WAGLOBAL_Admin_UserName = "yuoradminusername" ;
$WAGLOBAL_Admin_Password = "youradminpassword" ;
can be what ever you choose for your site's Admin area log-in and password. You can choose and insert these in to the globals file before you carry on with the install procedure, or change them afterwards if you want a different Admin log-in name and/or Password. When you want to change the content on the areas you have set up for content management editing on your site, you will need to log-in to the Admin area to make the changes using those details.
Where are you with the install at the moment? The first step will have been to set up a mySql database and created the tables using the .sql file included in the download (Database/CMS.sql).
That step and all the subsequent steps (or links to the necessary info) are in the 'Getting Started Guide' (although the bit about the setting Globals is referring to outdated documentation and is yet to be updated, but we've sorted that here!).
You may have already sorted all of that, - apologies if so. Let us know if you need any help with any of this.