@messiahman as you don't have a Z probe the easiest way is to set the home position to what it actually is relative to the bed. so if you home and it is 0.21 mm higher than you want it, adjust your homeall.g and homez.g files to set the Z axis to 0.21 when homing is complete.
The easiest way to find out what the correct abound of adjustment is is to use babystepping to nudge the head down until you get a good first layer.