I am not a linux pro by any means, but if you want to learn linux I would get a Raspberry Pi and install DietPi on it.
A RPi allows you to have a testbed where you can experiment and learn without messing up you main device. It’s also easy to format the SDcard with a clean image if your install goes haywire.
I like DietPi because it has a bunch of useful tools to get you accustomed to CLI linux. It makes it easy to install various home server services (NAS, media server, torrent client) that work well on the RPi. I find that getting results helps the learning experience. It’s also based on Rasbian/Debian, so you get to learn how Debian works.
AFAIK there can be significant differences in the terminal experience of different Distro families, but my experience is limited to Debian derived distros, so don’t take my word on it.