Hey there jackscruby7,
Welcome to the Chromecast Community Forum! I would encourage you to check out this article for more information on Guest Mode and where to find it. Here is where it is in the Google Home app:
I look forward to your response, and if you have any other questions or concerns for me, please let me know!
No problem at all. Do you have Local Network Access enabled? Here is how to check for that:
Let me know if that allows Guest Mode to show up. Also, make sure that your Google Home app is up-to-date as well.