After you've understood the concepts of groups, membership and content types, you'll want to figure out how to do what you need to do. Often, there's more than one way to do things, but not all of them are equally effective.
Normally, you can just leave yourself logged in and then you won't have to remember your new login name and password. With this site, you can put either your login name or you email in the login name box. If you forget your password, use the "Request new password" link on the login page.