Z axis depth wrong

I have calibrated my z axis but when it goes to carve it try’s to cut all the way through the wood in one pass even though the depth per pass is .02 The table is level.

How do you set it’s height … the “z-zero”?

With a probe or manually?

And to confirm, because I recall this point confusing me on my first cuts … you’re setting the Z height to the top of the workpiece, not the bed of the table?

All I have done is calibrated it

I think my problem is a warped table