Cartesian printer home position

I have a 220 x220 printer. Just upgraded from anet to a Ramps 1.4 with BL-touch.
I used to be able to home just x,y then center z probe to the bed raise home z. then start my bed leveling procedure.

my starting script and marlin

G1 Z20
G28 ; home all axes
G29 : Auto leveling
G0 Y200 ; Y-axis 200
G1 Z30 X110 ; E10 F600; centreing and raising and prime
M300
M0
G92 Z0

Edited 2 time(s). Last edit at 05/11/2019 11:04AM by headviking.

Ok I found my problem. I need to allow "#define Z_SAFE_HOMING".
This fixed my Z homing issue. Now i need to work on my bed probe locations. Not quite sure as to how to set them.