So, what would you do next if you were me?

Spend a lot of time here https://www.youtube.com/user/Depoalo...view=0&sort=dd

Also the Mach forum should be of big help.I know nothing about Mach,so I hesitate on telling you how to set-up your offsets.
You do not need a tool probe and touch plate though.There again I hesitate giving you information on how I do it because my machine is Worlds different than yours,but there are other ways involving a piece of paper and an edge finder.That is how I do it.
Engine Guy is a whiz with Mach,maybe he can explain way to do it in Mach the way I just described.It will get you going faster,which is what you want,right?