Gordon, good news: you can go ahead and try the programs without switching to Linux.
Nearly all free and open software (FOSS) is written to be multi-platform, so even though much of this software is developed on Linux, it runs on Windows and Mac as well. Therefore, much as I like using Linux, I have to admit there is no reason to switch as long as you are satisfied with how your Windows machine is running - you can still take advantage of nearly all the FOSS out there. (On the flip side, starting to use FOSS on your Windows machine will make it easier to transition if you ever do decide to try Linux. That was true for the example I gave above of my parents - they had been using LibreOffice on Windows for several years, due to not wanting or needing to purchase MS-Office.)
Here are some links to get you started with FOSS on Windows:
LibreOffice suite - complete replacement for Office360. (Click the Download Now button and if necessary choose your operating system - it should "sense" your operating system and default to it - probably Windows 64-bit if you are running a recent version of Windows):
https://www.libreoffice.org/
LibreCAD - very capable 2d CAD; I have never used AutoCAD, but I've heard people say it is similar in approach; has CAM features built in. (Click on either link under Windows and then click on the link for the latest installer; you'll want to run this program after it downloads; look in the Downloads folder and double click on the file name):
https://librecad.org/#download
FreeCAD - very capable 3d CAD, with rapid improvements being made; includes CAM; in addition to the mechanical design that is probably what you and I are most interested in, it includes various specialized "work benches" for things like architecture, ship building (!), and more. (Click on Download Now and choose your flavor of Windows, 32-bit or 64-bit):
https://freecadweb.org/
Note that there are tons of tutorials available for all of these. Note also the discussion (above? or might be in another thread) about the problem you can run into with a tutorial based on a different version than the one you are using. Where this will have the biggest impact is with FreeCAD, because of the rapid development. The current stable version as of this post is 18.4; for many basic tasks you would be fine with a tutorial based on version 17, maybe even 16, but there were some significant changes with version 18. And there are even more significant features coming in the next version (19) - and sometimes people put out tutorials on these new coming features, and you will wonder why you can't find that feature in the version you are using - DAMHIK.
I tend to like Sliptonic's you tube tutorials on FreeCAD, but he's been mostly quiet lately - only one recent video.