Hi Amron,
Welcome to the forum.
I think the first thing you need to do is read the Mach3 manual. Don't worry too much abourt the bits you don't understand at this stage (we all started out knowing nothing about Mach3) then come back with any specific questions you may have.
One thing to consider at this stage is that Mach3 is now obsolescent and you should perhaps be looking toward the future by using and learning Mach4.
The Mach3 Manual can be downloaded here:
https://www.machsupport.com/wp-content/uploads/2013/02/Mach3Mill_Install_Config.pdfTweakie.