I would assume cone cleaning would be the air blast while changing tools, to ensure that the tapers are clean, which should only blast during tool changes, but it could be an air curtain type thing to keep dust out the spindle.
You'll find out soon enough once it's connected though.

I'd personally wire and configure, so the push button activates through the software, just to avoid any chance of the button being pushed when it shouldn't, however I've never configured UCCNC so can't comment on how to do that part of it.