I am so new to this, I have yet to get the computer or the programs yet for my cnc router. My question is, do all I need to basically get started is one computer and 2  programs ( say Cut 2d and Mach3)? I used to draw up the part, print it, and use the coordinates to program the cnc mill where I worked. Will I be able to draw up the part on Cut 2d and enter the data directly to Mach 3 on the same computer? Or would I be drawing it up, printing it, closing the Cut 2d program, opening Mach3 and entering the data needed? How does this work? Thank you for your help.

Ususally you draw in a CAD program, open in Cut2D, generate toolpaths and g-code, then open Mach3 and load g-code. Cut2D may have some drawing tools, so you may be able to skip the CAD part. Not sure as I've never used Cut2D.

Oh. I was to the impression that cut2d was what was used to draw the part. Because all I want to do is draw up some diamond shapes, and then mill them. What would be a good cad software that would be the most user friendly and easy to use with Mach 3? Thank you.

Looks like you can only draw rectangles, ovals (ellipses?) and circles in Cut 2D. But you may be able to manipulate a rectangle into the shape you want.

Easy to use is relative, but there are plenty of free CAD programs out there.

A9CAD
ProgeCAD Smart
SolidEdge 2D

You can make diamond shapes in Cut2D. You would basically make a box then highlight the line and right click...then at the bottom you'll see edit node mode. You'll have to add a note at the midpoint of each line then delete the 4 original points.  But to answer your question you don't really need a drawing program other than 2D if you are planning on doing very simple and basic shapes.