To keep things simple, your email address is your username.
3. Enter your password
This is the password you created when you first followed your invite link. If you haven't done this yet, checkout the getting started guide. If you can't remember your password, you can reset it here.
If you've forgotten or lost your password, you can request a password reset link here. On the reset form enter the email associated with your BoardSpot account, and you will receive an email with a link to change your password.