How can I find my login name or membership pass number to do my online registration for my girls?

If you are registering using this system for the first time then you don't have an account yet. You need to create one so when you see that login screen, look on the right side of the screen for the "Create Account" option and start there. The first account you create will be yous as the main account holder/parent/guardian. Once you are set up then you can add family members to your account so that your children are all linked to you. The system will walk you through the process.