The link to the free trial will be in the welcome email sent during the signup. Please use the credentials (emailid, password) used for the signup to login. It is not possible to execute the automated tests on the free trial environment.
I have a similar problem. I've accessed the trial system using the link in the email, but when I try to sign in again it doesn't recognize my Pega email address (firstname.lastname@example.org) and network password. Any suggestions?
Strange!! - yesterday morning (European time) I couldn't access my "Express" instance using the link in the email. However, later in the day I could. This morning I'm having the same issue, ie. when using the link in the email I get the message "The request did not go through. You might not be a valid user on this system. Please use Platform Trial to signup for your personal trial."
Surprise, surprise - wait until later in the day and it works!! I guess it wakes up with the USA!!