I recommend checking your email for the confirming the account was created, and has your username and password. In case you  do not have that email anymore, request your username or password through the website, there should be a link for this at the logon page. The email you used when you signed up will be sent the username or password. 
However, this does require you to remember any secret questions and answers you may have entered during the signup process. If all else fails, connect the site administrator or technical support. They will be able to reset your password or tell you the username for that account.