Initial workpeice tooling set-up instructions using a pendant controller type machine

[JAZZCNC]

What did I do wrong? I'm missing something here and feel a little dumb.... Newbie cock up I know... Loooong time since I did this and it's a fun learning curve again

Don't feel dumb we have all been here in some form or another.! . . My first attempt with G-code ended thumping a perfect square hole thru 40mm of MDF after sending Z axis wrong way. . .Lol

I don't use V carve but If it's not that you have set the Zero point at bottom of material and you can't find any obvious reason then it could be the Control as a TOOL offset set.
Just like WORK OFFSETs you can have TOOL OFFSET's so your control could have TOOL OFFSET's entered into it.?
So when your G-code calls for first tool it applies the OFFSET set in the control. This could give the trouble your seeing.

If you open the G-code file you look for G43 H# with the number being the tool number probably 1 in this case. It will be some where near the top and probably will be near the tool number IE:
T1
G43 H1

If so then chances are you have TOOL OFFSET applied. Just remove the G43 H1 or put G49 straight after it.