So I just got my printer a few days ago(Creality Ender-2) and I need to adjust the z offset of the start routine. My first layer has some gaps, but all others are perfectly fine. There is a commented line in there that says something like "Move bed position down 15mm". Can I change the value from Z15 to something like Z14.5 to have the print head be 0.5mm closer to the bed at the first layer?

I searched over gcode command lists and its all quite confusing to me since a few of the commands seem to do similar things just not sure which ones I need.

On a side note my machine can do Z Offset through the control board, however I cannot specify negative Z values so that doesn't help me does it?

Thanks!