Audio/Visual Settings in Google Meet
The first thing to check is that you have allowed Meet access to your camera and microphone.
Steps to Allow Access in Chrome
Go to meet.google.com.
Click the lock icon (or settings icon) on the left side of the web address bar.
Turn on or Allow permissions for both Camera and Microphone.
The next step to troubleshoot your audio or visual issues in Meet is to do the following:
Open Settings
Select your microphone and speaker (audio) or Select your Camera (visual)
Press test on speaker to make sure you can hear (audio only)
You should be able to see person on other end and they should be able to see you (camera)