I’m hearing a lot of very poor advice in here, at least from my perspective as a Linux user who’s been through the gamut of various distros over the years.

Fedora atomic desktops are not beginner distros. That is not their purpose, and their limitations make many things a person may eventually want to do with their machine a lot more complicated.

Debian? Are we joking here? Debian is an amazing distro for what its purposes are, but it’s not beginner friendly. Debian is bare bones.

Linux Mint is the easiest answer here. Ubuntu LTS (or its classroom based fork edubuntu) is another great answer. I know every Linux user on the internet recoils in horror at the mention of Ubuntu but it really is a drop in plug and play solution for kids and old people.

just a heads up last I checked roblox wasn't officially supported on Linux, though this may have changed in the last 6 months.

KDE Plasma offers a UI similar to Windows out of the box, I would say that's a good start. Introduce them to the endless customisation options and they might start to dig it. Maybe take a distro aimed at gaming like Bazzite.

Other good options inlcude OpenSUSE or Linux Mint, the latter with another, but also similar feeling desktop.

Although caution is advised, this is a slippery slope to becoming a programmer.

Mint, Pop!OS, or Unbuntu LTS

I second any recommendation for a kde based distro. Ubuntu or it's derivatives are the easiest place to start. Kubuntu is the kde based flavor iirc.

My daughter just turned 6 and is competent with a mouse and keyboard. They have kid friendly houses and keyboards on Amazon for cheap. She's been daily driving slackware since she was 4 and has no idea how badass she is yet.

Gcompris is a great app. It's a bunch of games for kids to learn letters, typing, mouse skills and some stuff just for fun. Install it on whatever distro you land on. Also, tuxpaint.

Fedora Silverblue is basically Android.
You click on apps in a software store to install, it updates itself (without you noticing) on reboot, the terminal is entirely optional and almost entirely useless.

I've heard good things about the Gnome desktop environment. Ubuntu uses gnome, maybe linux mint you can get gnome on that. Perhaps fedora too.

Ok, let me rephrase this:

Your kid is too young to understand the concept of a mouse, but they arent young enough to not use Tiktok, a Social media known for killing even young adults attention time. And for some reason they are thought how to use a PC? To a 5-7 year old?

That aside, I recommend using literally Any OS and just making a guest user excluded from the sudoers file. To install new Apps, just use flatpak at user level, and for roblox theres Sober

Gnome + flatpack with no sudo privileges and your golden

Uh, I don't have a good answer for that, but I'd give them something like Linux Mint anyways. That way they can look up stuff, watch tutorials and don't have a super niche thing running. Or give them one of the popular gaming distros, if it's that.

Idk. Gnome feels very much like Android to me. And KDE follows similar design patterns to Windows. And kids and teenagers tend to figure out all the things they want. If they have the motivation to do so.

I'd just install debian because that's what I use so that's what I can most easily provide support for.

My opinions are likely to be in accord with information found at https://www.privacyguides.org/en/desktop/ and https://www.privacyguides.org/en/android/distributions/

As an alternative to making decisions without direct assistance, you might benefit from contracting with another person to make decisions based on requirements you describe (essentially getting a chief information officer (CIO) for yourself). The main reason I'm suggesting this is that having more people involved will make it more likely that someone will know about established best practices relevant to your situation or that someone will have experience with a problem that is similar to the one you're dealing with. Additional reasons I could provide for this would be similar to the reasons people give to discourage someone from handling court appearances without a lawyer or doing surgery on themselves. You might be able to use https://ryf.fsf.org/categories/laptops to find information about how to contact people about your computing needs. Alternatively, you could visit a store (for example, one operated by Walmart).

Mint, Trisquel. I couldn't run a software on Zorin (aldebaran choregraphe), I tried to solve it but unsuccesfully. So I had to change the distro. I chose Mint. Very friendly. Than switched to Trisquel because it's 100% free and recommended by FSF. But for someone who doesn't care about Free philosophy, I recommend Mint.