Recording separate audio tracks

Sorry if this is such a basic question, but I can’t seem to find the answer in the manual. How do you record subsequent audio tracks, monitoring them with head phones, but recording them separately? In other words, monitor the first track, while recording the second track, without recording the first track into the second. I’m sure this is simple, but I haven’t figured it out. Don’t laugh.

You only have to set up your audio hardware (which you are not mentioning) and your used software (which you are not mentioning) as explained in your Audio hardware´s (which you are not mentioning) and software´s (which you are not mentioning) manuals.