Thanks for the fast reply! The mesh grid line was exactly what I needed (M557)! I just had to tweak the radius down because I have a smaller bed.
For the Z probe, I figured out my problem. I was putting the gcode in for REPRAP 2.X, and I'm on 3.0 For anyone that ever comes across this looking for this answer, after plugging into the probe instead of E0, this is the line that made my probe work:
M558 P5 C"^zprobe.in" H5.0 F120 T6000
Also, after doing the autocalibration, I figured out how to do individual rod lengths for X/Y/Z, to adjust for slight discrepancies in rod length you just put it in as "L210:210:211" instead of "L210.33", I assume for X Y Z respectively (still testing that).
Now that I think I have everything figured out, I am really digging my Duet board. To think I almost got a hold of another 8bit noisy marlin board. No more juggling SD cards or dragging a USB cable and compiling every time I want to adjust or print something.