Here is a list of helps for setting up audio & video and resolving issues
Troubleshooting
Presenter's PP Shows a Black Box on the Screen
Shortcut: [Ctrl+Alt+Shift+H] (activate), [Esc] (deactivate)
Presenter can't hear video soundtrack while they are sharing
Audio Echo when using 2 Zoom connections to present
Zoom Audio Settings: Unencrypted Audio warning
Turning off incoming video (low bandwidth)
Setup
Screenshare Settings - Computer Sound & Video
Use of Spotlight and Pin video
Using Logitech Capture with Zoom
Zoom Screen Share Remote Control (Slides)