Hey there a3c3ee74f4,
Welcome to the Chromecast Community Forum! If you still need to set up your Chromecast with Google TV, check out this article here that explains the process. After you have the device set up, here is how to begin casting! If you run into any errors or issues, let me know.
I look forward to your response, and if you have any other questions or concerns for me, please let me know!