audacity mic issues

hi I am brand new to audacity. I have version 2.3.0 which I believe is the newest version. I am trying to start a podcast but am having all kinds of microphone issues. I was using a Samson Q2u usb plugin and it has been giving me an error message for my rec wording device. I believe error code 7779 and now it won’t even recognize my mic. I started just using the MacBook Pro mic in audacity and the built in Mac book pro mic is now making a high pitched noise when I hit record… can someone help me with this?
joy

Probably not. It’s more likely to begin with “-9”, and should include a message.
If you can tell us exactly what is happening, then that helps us to help you.

Also, there are some changes in Mojave from previous versions of macOS, so let us know if you are using Mojave.