To answer your first question, but into the template that Jazz provided - I use "Fusion 360 - Design" for the first step (Design), "Fusion 360 Manufacture" for the second (CAM), and UCCNC for the last (actual machine control). Or on the lathe I replace UCCNC with LinuxCNC - but only because the former isn't designed for Lathes.

The one 3018 engraver I've quickly looked at on eBay bundles GRBL Control software. GRBL is a subset of G-Code, that Jazz refers to above supported by a microcontroller-based machine motion controller (the PCB/brains included with the 3018) - that is a special-to-type instance of the machine-control software (the third phase of the software discussed above). You're likely pretty much tied to that in the first instance when/if you buy the 3018, so that helps you make a decision on the software tool chain.