the ability to pull up a stereo recording and work on just one side of the recording
Do you mean, choose to record only one channel of an interface that has two channels? If you are connected to the left of such an interface you can usually do what you want by setting Audacity to record in mono in Device Toolbar.
You can use the Audio Track Dropdown Menu to “Split Stereo Track” to left and right or you can Split Stereo to Mono. Use the [X] button top left of a track to delete it.
I work on one track of a stereo pair by splitting as Gale says, doing whatever to the side, then making the two mono back into stereo by using the drop-down.