To get started before I bought a better desktop I just used a garbage Windows 8 laptop. I ended up putting 16 gigs of ram in and loaded Windows 10 onto and it served me fine for a few months. it was a little tedious using Fusion 360 sometimes but once you get your workflow ironed out and understand what you can and can’t do in the sketch environment it should be okay.
That old laptop is still running my langmuir and I can do some basic design on it in the shop. I try to have all my work and toolpaths done and figured out on my desktop before I ever step foot in the shop to cut.
I ran it hot and hard