And basically something without privacy unfriendly bloatware (like Ubuntu).
Can you give a little bit more context on this? For what bloatware are you talking about? Ubuntu comes with a variety of open-source programs, some of which you can choose to not install during setup. It does provide full disk encryption.
Look, it isn't as privacy friendly as Tails or Whonix, but it is friendly in the sense that it doesn't spy on you by default (as in Windows).
When it comes to security, use a reputable distro with large community. That's why I use Ubuntu (and because I've used to it). If your computer doesn't fulfill the resource requirements, consider using the alternative Xubuntu, which requires even less resources.
You can also try out Whonix as it comes with Bitcoin Core (and is privacy and security focused):
https://www.whonix.org/.
You can read up on the whole Canonical-Amazon incident. Basically Canonical (company behind Ubuntu) sent supposedly anonymized telemetry to Amazon. Apparently there's some drama with RedHat as well (Centos). Ubuntu is probably just ok to use, but comes with a lot of stuff that I don't need.
Maybe I should just give Debian a try. Apparently it has now become manageable to install. Back then it was a mess but looks like nowadays it installs like a regular OS.