You'll get a QR code or setup key. Next, open the Google Authenticator app and tap the plus sign. Record the 2FA code/key. Whenever you're asked for the 2FA code, open Google Authenticator to find it.

As of today, Google Authenticator 7.0 is fully available via the Play Store. In terms of new functionality, you get the ability to search through your accounts instead of having to scroll.