I've got a music track recorded and imported into track 1.  Now I want to record guitar on track 2 along with music on track 1, WITHOUT recording track 1.  I want the guitar isolated on track 2.  I cannot figure out how to do it and the tutorial is no help.

This is a BASIC function of recording, recording an isolated track by playing along with another track.  Why it should be so complicated is beyond me.  Whenever I hit PLAY on track 1 I can see the music from track 1 on the levels for track 2....

it's infuriating.

In whatever sound card or audio interface you're using, there is a setting that will send the outs to the ins. It has nothing to do with MC; that just records what is sent to it,
Look for a setting called 'What You Hear' or 'Stereo Mix' in your sound card or audio interface's settings and disable it.
Some audio interfaces have a knob on the front or a switch on the back to enable/disable this "feature".
What device are you using to record and make sounds?

wow