It’s not terrible advice tbh, even just hand sketches are solid for getting ideas down, makes it easy to translate to cad. It at least helps me think things through and the like.
Get a few pencils with different leads (some harder stuff like 2-4H and an HB) and some nice paper and you’re good, but really anything works, totally have a mockup of my garage on a whiteboard planning where I want to put stuff.
As for cad packages, freecad, as far as I’m aware there are some architecture workbench plugins, and there’s a tech drawing workbench. Coming back to cad after a while I found it super easy to pick back up (coming from solidworks at least)
I bought a Brother colour laser last year (which on the outside looks identical to the monochrome one I bought 17 years ago that lives with my parents), zero issues, which pretty much has been my experience with printers on linux (also tried a ~5 y/o & 25 y/o HP LaserJet, one being the cheapest thing I’ve ever used, other being old office equipment, think I tried the Epson ecotank and photo printer my mil has as well)