You have filled the registration form but not activated the link sent to your email id.
The activation link has been sent from firstname.lastname@example.org
Kindly go through you mails and click on the link to activate your account. If you are unable to find the activation mail in your Inbox, do check your spam folder too.
Once you click on the link, your account will be activated and you will be able to log-in with your username and password.