Access to my microphone or camera was denied
Meet needs permission to use your camera and microphone in Chrome. You will be asked to allow access the first time you join a Meet video meeting.
You can change the setting to allow Meet to use your camera and microphone, click on the camera icon in the address bar and select the Always allow option.
If these changes don’t resolve the issue, try below options:
Confirm your camera is connected.
Make sure no other apps currently access your camera.
If you have more than one camera installed, make sure the camera you want to use is set to active.
Confirm you have the most recent version of Google Meet.
Enable your camera before you join the meeting.
People can't see me in the meeting
Make sure that your camera is turned on and your computer and browser are able to access the camera so you are visible.
Fix issues when you present
If you’re not able to present in a Google Meet video meeting, you should give your browser access to record your screen.
On an Apple® Mac® computer using macOS® Catalina® version 10.15 or later, let Firefox® or the Chrome Browser access your computer’s screen recording:
Go to System preferences > click Security & Privacy.
On the left, click Screen recording.For Mac users: On the bottom left, click the lock to make changes. In the window, enter in your password > click unlock.
On the right, check the Google Chrome or Firefox box.
Why is the meeting window displayed when I present?
Select a new tab when you present or a new tab.
If you present the meeting window, an infinite mirror can occur.
Useful link: Troubleshoot camera & presentation issues in a meeting