I think immutable distros could be great for newbies, but I’m just thinking they’re still so new that if you go online to look for Linux advice or help, most things you’ll find are very much not for immutables and I doubt a true newbie understands what’s what.
That’s also a reason I’d recommend something like Debian (although I’ve actually never even used it myself) because there’s so much compatible info out there. I would recommend OpenSUSE, even Tumbleweed, but there’s just not as much help or there to find as there is for Debian. But even with that said, OpenSUSEs snapshots and the way they’re configured out of the box is an absolute godsend and gangbanger for newcomers.