NebLem

Linux Mint and PopOS are usually listed as friendly distros and are derivatives of Ubuntu without Ubuntu controversies like Snap. Mint even has an alternative direct Debian base skipping some Ubuntu packages, so might be ironically closer to old Ubuntu in that flavor.

If you’re open to going non-debian, Manjaro is often sold as the more user friendly Arch. (Edit - a recent Manjaro controversy has people recommending EndeavorOS instead for an Arch wrapper. I’ve not tried that one myself).

Debian or Arch aren’t bad to use directly either and are far more newbie friendly than they were a decade ago even if not as out of the box opinionated as their derivatives.

In addition to Joplin, Logseq is really great too, though with more of a text-first, outline based, zettle approach.