Pop!_OS (Linux)

Pop is a great starting point. Others have mentioned Mate, Cinnamon, or Ubuntu, and those are likewise pretty easy to start with. Pop is the one that I install on my kids' and parents' computers, because it's that easy, and it's also the one that I use daily because it has some key features (I'll say below).

Hopefully by now you've already read or watched some videos about differences between using Windows and various Linux distributions. If not, here's one channel on TilVids (a fediverse version of youtube) that I think has some useful stuff: https://tilvids.com/c/thelinuxexperiment_channel/videos

This video from System76 also gives a short and straightforward intro to the pop desktop environment:

[Edit: actually, I should link to the pop os info page because the explanations there are more up to date.]

Here are my key features, in order of how I think a new user might care about them:

• the launcher: Other linux distros have a similar one, but pop's is a little more streamlined. On pop and the other distros with launchers, it's a little different and I think a lot better than the Windows/Mac versions. It's worth learning about and using.
• virtual desktops: All linux distros have this, and if you haven't used them before I highly recommend taking the time to get used to them. Pop has some nice features to make switching workspaces a little easier, but they might be the same or similar to other distros (I'm not sure).
• pop shop: Most linux distros have a similar thing, and actually I think Pop's version is a little worse (a little more laggy/buggy). But, as an interface for finding the software you actually want to install, it's way better than the windows/mac app stores. This is another thing that's worth learning and using, even though it's different. You might have seen a lot of arguments online about flatpak v.s. snap v.s. appimage (if not, don't bother). For a beginner, I think it's now worth suggesting to just use flatpak apps whenever possible, and you can find them in the pop shop.
• nvidia drivers: Only relevant if you have nvidia graphics, but if you do, the pop disk image with those drivers already integrated is much easier than figuring out how to set them up in other distros.
• window tiling: Pop is the only distro that makes this so easy to set up and use; at first I thought it would be terrible, because it's so different from what I was used to, but for productivity it's actually much better. Now that I'm used to it, I really miss it in other desktop environments. (It's possible to install a similar thing on other distros--this is linux after all--but my impression is that it's kind of a hassle.)