Hello Rod and welcome to the Cow Audio Forum
Providing your Mac has an audio in port and I think all do these days, you have a lot of solutions.
The trick is that the input jack is stereo, unbalanced. To feed it properly you need to use a stereo mic or a mic with a cable that's been wired to feed a mono mic to both input channels. The Rode VideoMic is such a mic.
Your other option is to use USB mic. USB mics have latency (delay in the headphones) due to the time it takes to convert analog to digital and back.) That can be very disconcerting if you are wearing headphones while recording your own voice. If you're not wearing headphones, it's not a problem. The Audio Technica 2020USB is actually a very decent mic in this category.
Regards,
Ty Ford
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