newbe CAD/CNC question - trying to get past 1st base!

Here I am trying to pick cad/cam software, trying to draw parts. I
just don't get it! The part I am trying to draw is a motor mount for
an RC motor. From the bottom view there is .25" left/right
border, .5" top/bottom but the difficulty is the cut outs in the
middle. The center it a 1.25 pocket (square), along the .5" sides is
a pocket (in .25") at 1" (.5" wide), beside that is another pocket
at .5" (.5 wide) and beside that another 1" (.5 wide). Keep in mind
my CAD experience is measured in days (thus this may be a really dumb
question) but once you draw the boxes representing the different
pockets how do you get the CAM software to generate the correct
stuff? I've tried a number of them (DeskCam2K (demo) and a few
others). I can't get any of the demo packages to treat the different
pockets as individuals. I've tried using levels but it appears that
CAM programs don't see them. Do I need to make separate drawings
each representing the pockets for particular level?

One last piece of information; as you may be able to tell I'm trying
to draw this in 2D (havn't even figured out the 3D drawing thing yet).

For CAD I've tried Dolphin (no help because I can't save not will it
open the CAM from the CAD menu; at least not in the demo version),
DeltaCad (I can draw in this nicely), and BOBCad.

Thanks,
Ken