This article explains how to find the MAC address of a Google Home device. You can find this information in the Google Home app after adding the device to your home or during the initial setup process.
How do I find the MAC address of Google Nest Hub 2?
If you need your Google Home's MAC address to connect to your network due to MAC address filtering, you can find it out with the following steps.
At the Connect to Wi-Fi step, tap the three dots at the top right of the screen.
Select Show MAC Address.