Y axis: In Config/Ports and Pins - Motor Outputs, reverse Dir low active (if it is ticked untisk it or vice versa)
You downloaded and installed Mach3 Demo. Limitation is 500 lines of G-code, and some others (can not remember). You should buy the licence and not to use "the provided pirated one".
Proximity switches: Check in Piort and Pins - Input Signals that desired Home/Limit inputs are enabled and correct port/pin selected (Home and Limit switches could be "combined" i.e same switch can act as Home and Limit at the same time.)
Round brass dosk: Touch sensor for setting Z0