Tinman has it correct.
My cheap advice is to learn "AnyCAD" and AnyCAM
Explained. Geometry is geometry, all systems do this.
Gcode is Gcode same with CAM systems
If you gain an understanding of the core of what and how this functions, you can do any cadcam system..
I have learned this during the development days of CAD and CAM when everybody developed everything and now weird systems are everywhere.
Here linked is the Latin of this business, learn it and make 150k / year.
If you can comprehend this there is no system you cannot master.
APT360 Programmers Manual
Nobody really uses this anymore. its the knowledge now
Oh yeah I forgot to mention, you may need 10-20years on the job in aerospace. to get a contract chance