The message "Go to Wi-Fi setup" is displayed when I try to sign in to my Google account and I cannot exit from this screen.

If the message "Go to Wi-FI" appears, press the HOME button to return to the HOME screen.

To sign in to your Google Account, you need to connect your TV to the network. After completing the network settings, proceed to Add account to sign in to your Google Account.

For network settings:

1. Press the HOME button on the remote.
2. Select Settings.
3. Select Network in the Network & Accessories categories.
4. Select Network Setup.
5. Select Easy.
6. Depending on your network environment, select Wi-Fi or Wired Lan.
7. Please complete the procedure in accordance with the screen instructions of each item.

After completing the network settings, perform Add Account again.

To add Google Account on Sony's Android TV: 

1. Press the HOME button on the remote.
2. Select Settings.
3. Select Add account in the Personal.
4. Insert your Google Account.