The standard wake words for a Google Home device are "Hey Google" and "OK Google", but as I read recently you can also use "Hey Goo Goo". No clue if that was intentional on Google's part or if the device just can't distinguish between "Google" and "Goo Goo". Nothing particularly useful here, other than being able to startle a friend with your in-depth knowledge.
But for some laughs, watch this hilarious YouTube video of an Italian grandmother trying to interact with a Google Home. ROFL!