Marlin Autoprobe checklist

I don't think my RichieC Marlin's Auto calibration is set up correctly. Can someone running me through the process.

I'm running RAMPS 1.4. I have a micro switch connected to Z-Min (pin 18) Not sure if it is NO or NC. How can I reverse it in the firmware?

Do I need to comment or uncomment anything in Configuration.h or pin.h? Or am I ready to go with my basic motherboard 33 set?

I know I have to set the probe offsets etc. but not sure if anything else inpin.h needs alterations.

Thanks