My Z offset is off

In lightburn not a problem.

First learn good use of lightburn. Read the snapmaker treads on the lightburn forum. There are many. Some with good explanation how to configure the snapmaker.

If all good? The only thing that you must do, setting the correct thickness for the material, speed and power for each layer.

Have you set the start from: to current position or user origin? You must use absolute coords.

Tip: Accurate, Repeatable Laser Guide