A beginner friendly distro like Linux Mint will probably serve you well.

Linux is great for the highly technical minded, who can fix anything themselves, and the tech-illiterates who basically only ever use a web browser and maybe something like Discord. As long as you remember to use the built-in app store (it’s not really a store, you can’t buy anything) as often as possible, you should be alright. You may need to unlearn the “Google software name, look for download button” approach that most Windows users have taught themselves, because there’s a good chance you’ll only make life harder on yourself if you try to apply that on Linux.

The tricky part is that as you get more demanding in your technical needs (like if you want to run Windows programs) the nice clickable buttons are soon replaced by command line scripts. It doesn’t help that a lot of online help articles about Linux will tell you to open up a terminal the moment you run into any kind of error message, because it’s very likely they the skilled people helping others for free only ever use the terminal themselves.

Then there’s gaming: if you use Steam, you can play most games out if the box, but outside of that you’ll find yourself reading wikis and messing with settings, maybe even changing numbers around in text files. The Steam Deck made a lot of Linux gaming super easy, but the focus for that is obviously on Steam games.

With most flavours of Linux, you can download Linux to a USB drive and run a full install from there so you can try it before you install it. It’ll run slower (possibly a lot slower), but you can experiment and click around as much as you like. Unless you actually start the installation or start editing files on your hard drive, the moment you shut down the computer, all of the stuff you did will be undone. Remove the USB drive and Windows will boot right back up.

As for the performance impact: it’s hard to say. I find Linux to be smoother than Windows in terms of general performance (and on my laptop the fan is making less than a third of the noise it makes on Windows!) but it’s not some kind of magical “make your computer twice as fast” button.

I would recommend you try a live disk (just follow the instructions on the Linux Mint website) and see if Linux is for you. If you don’t like how Mint looks or feels, there are alternatives you can try (Kubuntu may be quite familiar to a lot of Windows users!) but you will have to decide if Linux is for you.

Something I haven’t explored myself, but may be good for beginners, is ZorinOS. There’s a free version and a paid version (the paid version lets you turn the OS into something closer to Windows or macOS) but the distro tries to be the go-to beginner friendly Linux.

Lastly, and I may get a bunch of downvotes for this, consider Google’s ChromeOS Flex. It’s a Linux distro that’s basically what’s on Chromebooks, but for normal computers. It’s quite fast and nearly indestructible to normal users, at the cost of having to use either Google’s applications (Chrome, Gmail, etc.) or having to use command line stuff to use normal Linux programs (Firefox, OnlyOffice). It’s not entirely open source, which is why a lot of diehard Linux users hate it, but if you look at it like a sort of “alternative Windows” rather than a “get rid of the corporate overlords” OS, it may be a good match for you.