The Virtual Box console displays a linux terminal. You are wanting to perform bash shell commands as described in the "Customizing Security Requirements" mini-course.  [email protected]/install is how you log into Pega through a browser aimed at the prweb webapp.

The root password is "password".  As root you can change the password of any user.

EX:   sudo passwd architect

The above will ask for the root password, the prompt you for a new password for the user named "architect".

To see "who" you are currently, enter "id".