Nostalrius Begins - Quality wow vanilla realm (1.12)

Hi, new user here. I just made both my forum and in-game account as per the directions, but I keep getting the "Disconnected from server" message when logging in.

Hey Fancykong,

You may be connecting to a test realm. You'll see the realm name at the bottom right of the login screen. If this is true than log in and hit the Enter key quickly as soon as you see Success then change the Realm to Nostalrius Begins.