Cannot really help with the Win10 thing (beyond what I did on Win11 to disable Copilot, which was probably more just "make inconsequential"[1]), and I
couldn't run gpedit.msc. You're probably at least as capable as me on that, from what you say.
So, instead skip to, not necessarily in the order you ask:
I would not know where to begin learning linux or if there are compatibility issues or what.
"Learning Linux" (and learning of compatability issues), I'd do by trying a "Linux boot on a USB stick" installation (available for many of the possible flavours you might want to try). Probably the least disruptive[2] and most effective way to get a good go at what living your chosen Linux distro would be. May give a few initial/intermitent performance bottlenecks, compared with a full install, but should be enough to check that your graphics hardware is fully supported, etc.
Unless you're going for a really specific distro (e.g. pared down interface, including non-UI, or focused heavily on something like being a media-station/pen-test/etc platform), the GUI[3] shouldn't be too hard to adapt to. The taskbar (if any) might default to a different edge of the screen. The equivalent-to-Start-button menu quite probably will
return in a way default Win10/11 lacks, unless it's designed to look like the MacOS-style "scrolling floating icon bar" or whatever
they do now. You should be able to navigate any 'popular' flavour of Linux (including popular sub-flavours of particular distros, which bend you to particular Window Managers, Themes and default configurations).
I suppose you can't be using Microsoft word, or Adobe?
You probably can, with different degrees of effort. I think you can use the webapp Office365 (with subscription), there
may be a port for the/a standalone version (like there is/was for Mac) and there's maybe ways of using WINE or even full on VM. Personally, I tend to use only LibreOffice/OpenOffice anyway, even on my MS OSes, as I prefer that to whatever MS has been doing to its Office Suite, and that
of course tends to be easy to install (or is already installed) under almost any Linux.
Not sure about Adobe. The Open-/LibreOffice seems to have sufficed for PDF-writing, I imagine the PDF reader is also available (my PDF Reader app on my Android appears to have picked up all kinds of things I associate with the Writer, and seems to semi-pester for a login account, so I don't know what's going on there).
Anything else will probably also have a FOSS port, a FOSS
equivalent or you don't need because its functionality has been integrated into something else that's on (by default, or installable) any Linux with a decent package-manager scope. Or, as last resort, WINE/VMing can be used (to variable fuss and performance hit). That latter may be necessary for specific applications, e.g. games.
I actually first ran DF at
home under WINE on my Fedora machine, many years ago... didn't run appreciably slower than on the XP machines at work (I 'benchmarked' hardware by running an overnight worldgen, back when worldgen was
that intensive), but obviously not a big hit on graphics. I also ran XPlane (MS Flight Simulator 'equivalent'), as it came with both Windows and native-Linux installable on its CD(/DVD..? no, probably still just CD... or CDs, but probably singular... must dig up the box), and probably ran better off-MS. Probably won't hold true for everything, especially if already a big-budget PC-port-of-primarily-console-release.
Can you buy a nice PC with Linux installed from a major retailer like Dell without massive issues?
Not sure about Dell(-likes). At certain times, there's been been an OS-lock-in by MS, insofar as in return for favourable OEM-licencing there were
no easy ways to get hardware-only or hardware-with-Linux alternatives to the default hardware-with-Windows one. You were limited to getting such a with-Windows machine and over-installing or dual-booting your chosen OS.
Buying the bits myself was the way I did it, though even then I tended to shell out for the Windows OEM (one of them I installed on half the disc ('system' partition and 'data' one) put Fedora on the other half (with its EXT<N> partitions, plus mounting the FAT32 'data' one), ended up doing almost everything via Fedora, never got around to doing the licence-verification of the
legitimate Windows licence, ended up repartitioning the Windows partition to minimum necessary to give extra shoulder-room to the Linux... could have saved myself a few GB as well as some GBP, had I anticipated this direction).
..But that meant making sure I was putting together my own decent combination of hardware (the best kind of DIMMs for the Mobo, a video-card/on-board GPU that wasn't awkward to get Linux support for) and without the ecomomies of scale that absorbs even a with-Windows and additional manufacturer-markup premium into the costs of a "cheap but not basic" baseline machine. Doing it from the ground up is not something
everyone wants to do. And the two main component-retailers I last used for such a task have
both stopped selling to the likes of me (one entirely gone out of business, the other stopped their public-retail activities to concentrate on B2B services) so I'd have to do yet more legwork before trying the same again.
And of course, is Linus pulling the same thing so it wouldn't be any better, or is it an improvement?
Mr. Torvald is a long way from pulling the strings. If there are any distro-type 'lock-ins' that you don't like, you can probably just avoid those particular distros. Go with something like DamnSmallLinux or PuppyLinux (or equivalent active low-footprint ones), being prepared for it being
very basic ('out-of-the-box') and needing some work to "make the use less effort" if you have certain expectations. Or even go the Arch route of being expected to do quite a lot to build it up from the ground up to get a "fleshed out" personal installation.
I tend to avoid the *buntu family, for the opposite reason, they seemed to be often made as OOTB 'easy to use if you're coming from Windows' (or Mac), where I quite like some of the flexibility not to be hidden behind 'wizard helpers'. But generally you hear advice for new users to try something like Ubuntu (or Mint, a "more efficient" version of Ubuntu) for more seemless transition. Can't tell you what these types are like at the moment
or what would suit you. But at least LiveCD/LiveUSB versions seem to be easy to try out without disrupting you current Win10, if you want to dip your toe in.
I guess how easy is it to switch to Linux?
Probably, if anything, too easy to switch (at least for a possibly unsatisfying or inconclusive taster). But whether you can discover a switch that you then want to
stick with would depend upon what you are looking for and what example(s) you end up looking
at. Could be a marriage made in heaven, or might need a few more swipe-rights to eventually get your ideal Tinder-equivalent of OS dates.
And I don't think I'm actually even a particularly up-to-date expert on all the possible options (like I said, I have avoided the whole *buntu 'family', and what I have recently used is more due to historic favouring and inertia than looking around for yet another "best option, for me". But, as far as generalising is concerned, I can probably...
in general... cover a lot of the ground widely but sparsely.
Someone else might be along shortly to let both of us know of any gross errors or notable omissions I've made.
[1] e.g. Taskbar>"Copilot in Windows (preview)" set to disabled, as with all things but "Task view" (no "Widgets", etc)
[2] But I don't actually know how much the option of WSL/Windows Subsystem for Linux does to also "not run Windows" while doing its "not actually a VM" thing. It's advertised as removing the overhead of the dual-boot setup, which makes me think that the dual-booting is not what
I think of as dual-booting.
[3] Assuming you still
have any semblence of GUI, of course.