My yamaha did not come with the optomizer mic

You can, and the results might be better than not optimizing, but they might be worse.
The optimizing process listens for resonant frequencies in the room (what pitch "rings" longer in your room) as well as damped frequencies (what pitch sounds "dead" in your room)
To do this, it needs a mic that's matched to the unit.

Different mics have different frequency response curves, so your friend's mic might think (for example) that 2500hz is really hot, but the yamaha mic would think it's normal.

Certainly won't hurt to try, but if you don't like the way things sound after optimizing, then just reset your yamaha to the default EQ.