Start off with Gentoo to get the hang of the basics. Switch to Arch because compile times and heat burns. Try Linux from Scratch for a laugh, giggle and move on, but with a new found respect for distro maintainers.
What’s your use case? If it involves AAA games then that will narrow things a bit but if you simply want a bit of docs n that and, internet browsing and a spot of email and realtime sound and CAD then we’ll need a broader chat.
Debian, Fedora, Ubuntu, OpenSuSE, Mint - those would be my starters for 10 in no particular order. Pick yours and your hip angle. I personally run Arch (actually) and Gentoo. I don’t recommend them as a dip your toe in the water job 8)