In a Meeting, you may check your mic, speakers and webcam under Audio & Video Options by clicking the 3 dots in the top navigation menu:
Choose your Mic and Speakers and see if your webcam is sending your video feed. Otherwise, check the drop down menu for your device to be listed.
To ensure your Mac OSX is in alignment with your choice in devices, navigate to System Preferences > Sound > Output and respectively go to System Preferences > Sound > Input to check your mic and speakers on your Mac.
If you encounter an error such as:
Check your device permissions in Privacy & Security under the Privacy tab:
Verify both Microphone and Camera for Intermedia AnyMeeting are checked.
Important: MacOS Catalina introduced a new screen where you may need to grant access to screen sharing. You may experience a blank screen if you do not grant this access in Security & Privacy options.