In the beginning it seemed like everything was a task -- how do I install new software, how do I set up the right display or printer driver, how do I upgrade the whole OS? Then it quickly got down to making things look and act in a way that made more sense to me, or even adding and moving things around on the start menu. Back when I started, setting up dual monitors required manually building an X11 startup file and upgrading the OS usually meant compiling a new display driver, but that was around 2005 so of course things are MUCH better now.

Eventually you'll get down to the point of simply finding compatible software to reproduce something you did in Windows, which usually isn't difficult. A lot of this is going to depend on exactly how you use your computer and what you expect from it. I was already using Firefox and Thunderbird when I made the switch so that covered like half the things I needed at the time. Microsoft Office is (thankfully) gone although some parts of Libre Office still feel a bit rough. There's pretty much no remaining support for Adobe pdf files, so if your employer makes use of advanced features for filling out forms then you may run into trouble (of course standard PDFs are very well supported). You will find things along the way where some business has made a point of locking people in to their product and there's not much you can do except point out to your employer that they're buying licenses for something that is free and more widely supported in open source products, but mostly you'll just find your own solutions to work around these issues.

That mindset unfortunately leads you to being locked into vendor-specific ecosystems with no control about the software you're using. The big vendors (MS, Apple) know this and have already started extracting more value (in form of data) from their users. Next step will be to put more stuff into their clouds and sell you a subscription. You'll be renting software with included spyware then. With zero control yourself. Linux and FOSS gives you control back. It's also quite easy to use in 2023.

It doesn't really take long to get the basic stuff figured out though, but there is definitely that initial feeling of being lost. As others have suggested, start out running something in a VM on your Windows desktop, then you can quickly go back and forth to practice doing things in linux as you have time (plus it's a huge benefit to have a working browser in Windows so you can do a search if something breaks).

Linux has a number of different desktop environments to choose from, and what's cool is you can load up multiple types and select one at the login screen. If you want to start with something that is reasonably comfortable, try loading the 'Mate' desktop. Maybe I'm just used to old-school Windows (Win2K was the last one I used), but I've always thought Mate did a good job of putting all everything in logical places. As for the OS itself, there's also been a lot of suggestions so I'll throw mine in as well... I'm a die-hard Debian fan, both on my desktop and on my servers. It does NOT push bleeding-edge releases on you, so this means you won't have the very latest updates but to me it's more important to have a rock-solid system that I can always rely on. I've been using it for about 15 years now and it has never failed me.