If you have Fusion 360 figured out, your most of the way there.
Most people with little computer experience seem to have the most trouble with the CAD/CAM part.
The machine control part is not that difficult.
I'd recommend UCCNC rather than Mach3, which is the control software that the Stepcraft comes with.
Before jumping into a build, I would recommend spending at least 2-3 months, reading and learning as much as possible. It will save you money in the long run.