Get a Kobo. They are excellent. I had a 2020 or so Paperwhite from 'zon but it made me feel sad all the time. My Kobo Libra 2 has caused me to read more since I got it than the entire before portion of my life.
If you get any books off amazon use calibre and DeDRM. IIRC DeDRM has stopped but also has been forked on git and continued by someone else so you would want the more up to date fork. Adobe digital editions DRM or whatever it was called I believe can also be removed up to a certain version but you have to download it for the first time with an old enough Adobe app version get the old drm version or it will get permanently locked to the newer version that can't be removed. Anyway removing DRM let's you read the ebooks on whatever device you want. It's not illegal in any country I have bothered to research except if you are doing it to distribute or sell.
As a side note if it helps anyone, I was able to get the whole procedure to work on Linux too by installing the required versions of kindle desktop and Adobe digital editions via Lutris and wine. Calibre and plugins are already cross platform.
Edit: updated DeDRM fork link because goog search results are utter shit these days. https://github.com/noDRM/DeDRM_tools