That sounds good, but to clarify MeshCAM is a CAM package, not a CAD package—you’ll use MeshCAM to generate tool-paths for the Nomad, but you need to feed it designs, which is where CAD software comes in, or files from Instructables, Thingiverse, etc…
Before your Nomad arrives I’d recommend taking a look at some of the options and “workflows” available to you for creating the files that you “feed” to MeshCAM. You’ll need to get some tools if you’re looking to do any of your own design work, and it’s also still helpful just for altering/adjusting the files that you source online to suit your needs.
I’d suggest taking a look at 123D, SketchUP, Fusion360, TinkerCAD, just to get your feet wet and see what’s out there. If you google “free CAD” you’ll get a lot of options, and there are some professional tools out there that have inexpensive hobbyist licenses too. You might also want to look at 2D graphics programs if you’re thinking you’ll do a fair bit of 2D work, because you can import a few 2D formats and then arbitrarily extrude them in MeshCAM to a specified thickness to cut out.
Once you’ve taken a look at the options out there, I’m sure you’ll have some more focused questions the community can more directly answer. Good luck and let us know what you pick out!