Grab an old Thinkpad and Install Arch from scratch following the wiki. It's considerably easier than e.g. Gentoo and equips you with enough experience to debug things.
Grab a note taking app like Joplin / Obsidian too.
After that try writing a pkgbuild and configuring sway/Hyprland/DWM.
Keep something simpler for daily driving so you don't get warn out (eg EndeavourOS/Fedora/OpenSuse or something along those lines).
IME Endeavour is a nice compromise between over engineered bespoke behaviour like eg Ubuntu and configuration pains like Void / Gentoo.