Working space set up

Here is the position that the Lightburn reads for me: X = 3.5, Y = 9.16. And I’d like to set this position as my Zero Zero as it is it the far lowest corner of my working space. Or if I could set my working size from -3.5 to 3.5? the Y axis is good as it is…

That isn’t a LightBurn setting, but one in your machine settings / firmware. Your machine shows GRBL, but what kind of system is it? Do you have homing switches? If not, it will be a little harder to do this.