This is probably really simple for you. There are 2 people speaking in my new podcast, but one sounds louder than the other. How do I make it so that they sound about the same volume? I recorded them on the same track.
That's a case for a compressor. Depending on the quality of your recording, you'll also want a noise gate.
Or turn the volume up and down manually every time the speaker changes (that's called automation and basically any DAW offers a number of things for doing it). That's a whole lot of work but you'll likely be finished before finetuning an automated solution.
And next time, use more than a single channel. If you already do (namely, used two microphones and have "one" stereo track), try fiddling with the balance control: that would by far be the easiest way of salvaging, well, the balance.
A compressor can help to some extent.
Set the threshold so that the louder voice gets quieter and the quieter voice does not.
Adjust the ratio, attack, and release so that when the louder voice gets softer it still sounds natural (not pumping in volume, not distorted).
Adjust the make-up gain to bring the track up to the volume you want.
YouTube has lots of useful information about how to apply compression to vocals. Even if a video is about compressing a single vocal, you may find it helpful. Sometimes the a speaker/vocalist varies their volume too much, and some of the the techniques for addressing that are also helpful for handling different speakers.