Ideally you'd spend at least a day or so trying them all, and about a week reading and watching about their differences, pros and cons.
Unless you are using nVidia for gaming or have an obscure hardware configuration, chances are you're supported wonderfully well at this very moment, by at least 2-3 distributions (Mint, Manjaro, Fedora, Ubuntu, Bazzite, SteamOS, PopOS, CachyOS -- you'll also have a choice KDE/Gnome).
All you need is pendrive. For the super easy transition you'd want an entirely separate system drive (nvme for example). I know, its expensive. I said for the super easy transition, its not necessary. Slow portable disk to store your current documents and game saves should be enough.
We live in the exciting times.