This is also how to create a new account. Just click the "Sign in to Your account" link on the above page, and you will see the option to create an account. You'll want to have about 15 minutes of time, a phone with a camera, your driver's license and either your Social security Card or Passport in hand. Often times this is easy and simple, but occasionally you have to do a video chat to finalize, and this can take an hour or more. BUT DO IT ANYWAY!!!
This is less about what you can do now and more about the future. This system is going to be the primary way to interact with the IRS going forward. So...
Set up an account, keep the password current, and check the account for any new information at least once a quarter. Letters from the IRS will be accessible