Note: The official Breakout Rooms feature is only available for people who are using the Enterprise version of the Google suite of tools. If your school does not pay for the Google tools, but instead uses the free version, you will not have the breakout rooms tool, as well as other Enterprise features. I do have a separate video where I cover an alternate way to do breakout rooms in Meet if you are using the free version which you can see here: Breakout Room Alternatives for Google Meet
However, for those who have the Enterprise version of Google Meet, I have put together a short 5-minute video on how to use the official Breakout Rooms feature. See below for the video.