Almost all the microphone is mono unless it's a housing with 2 mics in it. Having said that, Windows computer would still split mono input signals into equal parts left and right. So recording on a Windows computer, you can easily select the stereo record mode and get the stereo tracks without post-production (though of course, that is not the authentic stereo).
But the situation is different on an Apple computer unless you use the stereo microphone to input, and audio is being panned only one way or the other. You can’t choose a stereo setting on recording software, but can only post-produce to make the two tracks. Basically, you just need to duplicate the mono track and set the original one and the copied one as left and right channel. Here are the methods for Audacity and Garageband (Logic Pro X).
3.“Track”→”Add New”→” Stereo Track”
Garageband/Logic Pro X
1.Create a second track in Garageband (empty for the moment)
2.Duplicate the audio of the first track, then move it to the second track
3. Use the "L/R" or balance control in each track to set one track left the other right.
If you want to figure out how this works out with other recording software on Mac or would like to suggest any other methods, feel free to comment below!