You can enjoy some functions of the Android TV even without a Google account logged in. You can watch TV programs and enjoy all Sony applications such as the Video & TV SideView app, home network functions for the Album app, the Music app, the Video app and the Network Electronic Program Guide (EPG).
In addition, certain functions such as the Google's voice search function, Chromecast built-in (Google Cast) function, Internet browsing and the YouTube app are available without logging in to a Google account.
However, you will not be able to rent or buy Movies, TV shows and Apps from the Google Play Store.
*Google, Android TV, YouTube, Chromecast built-in and Google Play are trademarks of Google LLC.