I've never concerned myself with the 0,0 reference as it's never been an issue. I just start drawing and, in the end, it never seemed to matter if the contents of my drawings went -0,-0 or +0,+0. The resulting drawing, and mainly the print-out, have always been usable. And...DeltaCad really doesn't care. The 0,0 -in DeltaCad- is simply an internal "starting point" that can go many thousands one way toward the plus side and just as many toward the negative side But in the end has no bearing on the final drawing.
In my opinion, there is no need to establish a "0,0" point reference in
DeltaCad unless you are dealing with pixel references such as may be needed for a web page, other digital graphics intended for large prints which may require specific (to-the-pixel) cropping and/or resizing or precise CNC projects.
My suggestion, don't worry about the position of the "0,0" location and just commence to creating your drawing.