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)
Feel free to dive in, the water is lovely.
I remember my brother ringing me and telling me that he'd managed to wedge 40MB of RAM into his PC. Yes MB. That was when a 1MB stick costed about £30 a pop. It seemed rather insane at the time. Bear in mind that on DOS/Windows machines at the time, you fiddled with himem.sys and autoexec.bat to wrestle memory regions.
Several years later I got a T shirt from Novell (Cool Solutions) for a pretty decent boot floppy disc image that was able to run with a lot of different network cards and still manage to run "ghost" without falling over.
Much earlier, I upgraded my 80206 PC with 1MB of RAM with an 80207 maths co-processor so I could run AutoCAD on it. Yes it did! The next version required 32MB of RAM, which at the time looked pretty mad to the likes of me.
32GB RAM ... ... modern apps generally will use whatever you have. The OS will disc cache, if nothing else.