If you don’t own or want to own CAD software, OnShape is a free in browser CAD package that I’m finding extremely helpful.
From what I can tell it is built by a group coming from SolidWorks (SW), and as I’ve done the majority of my learning around 3D modeling in a “questionable” copy of SW having the somewhat familiar interface is a big plus. Another major plus is that the CAD package works on Desktop browsers and in Phone browsers and Apps.
The catch on this is for FREE access, all your models are publicly visible on the internet. So if you can handle that, this is a very nice CAD option.