In my renewal email it tells me my password for myAA is my date of birth. Why is it not working?

This is incorrect, your date of birth is the password to access your attachment in the email. To renew your policy, you will need to access myAA. If you have logged in to myAA before you would have created your own password, if you have not you will need to create a new password. If you forgot your password, you can request to change it.