Hi Aaron, thanks for your question. It sounds like you are creating/setting up your account. When you do so, you'll need to input your username (email) twice and your password twice. To finish creating your account, we will send a verification email to the email address you used - this is a security precaution. Once you get that email, you can click on the link within it and that will provision your account on our servers. At that point, you can click the link in younity (on your computer or on your mobile device) telling us you have verified your account. Your account is now created and you can add additional devices to your heart's content (using that same account user/pass combo).
Does that make sense? Please let me know if something is not working or if I misunderstood your question. Thanks.