Hi,
Fusion 360, made by Autodesk, the same company that makes AutoCAD, Inventor and HSMWorks, has made a splash
because its free to hobbyists. It is by no means the only CAD/CAM program around but it is a good one.
Often you have a very simple job for which you don't require CAD/CAM, maybe cut a rectangular slot, drill a bolt pattern
and face the material. NFS MillWizard ($75) is good for chaining simple operations together. It gives what amounts to
'conversational programming' to Mach. I use it a lot.
Craig