Go to the Single Sign On webpage https://sso.webcentral.navymwr.org and Accept the User agreement.
Enter in your email and password provided in the email from Navy Single Sign On <firstname.lastname@example.org> and click Sign-in to proceed to the multifactor authentication step.
Sometimes email from SSO is routed to Junk Mail, so please check there if you do not see it in your inbox.
Choose a method of Multi-factor Authentication that works best for you. Multifactor Authentication is a two step process that only grants access after confirming your password (something you know) along with a PIN or Device generated Code (something you have). Based on which method you are using follow the links below to setup your authentication method.