A Few Tips:
CLOSE EXTRA TABS: Live video chat takes a lot of the computers brains. It will work best if there aren't other things running and that includes other tabs and windows.
HEADPHONES: Extra noise can get bothersome.
If you happen to have headphones with a built in microphone, that is your best option.
You can also use a regular set of headphones and the built in microphone of your device.
ALLOW CAMERA AND MICROPHONE: The first time you use a video chat, it will probably ask for permission to access your camera and microphone. Without this permission it cannot access those. On this note, if your camera or microphone aren't working, check to make sure you've given permission.
SPEAK CLEARLY: The program does try to block out extra noise. If you speak very softly, it might mistake you for extra noise. Speak clearly and loudly, but don't yell. A #2 (Tabletalk) voice should do the trick, and at times you might want to pull out a #3 (Presenter) voice.