Go with Bazzite (if you end up liking it, you can install it on your steam deck, which will be the same process you use to install it in your laptop… but that’s for the future.)
Mint is okay, but it’s a bit behind and you have a greater chance of something going wrong than with one of the atomic distros (Bazzite). With atomic distros all the important stuff you can’t really touch and the only things you can change are your personal files that are important to you but don’t affect the system at all.
As long as you reboot your computer from time to time, it’ll always be the latest everything. And if something goes wrong with an update, you just choose to boot into the previous version you were just using and everything is back to how it was. Non-atomics you can affect files that are important and you have to stay on top of updating.
Between that and being built for gamers it’ll have everything already installed for you, though if something is missing, just click to install from the “app store”.
When you go to bazzite.gg to download it, you answer a few questions about your hardware, and pick a desktop environment. Some others have touched on Gnome and KDE for desktop environments, the choice is yours. Do you want a desktop that looks more like windows (or desktop mode on your steamdeck) or do you want it to look more like a Mac? Windows and highly customizable is KDE, Mac and just use it as is but still able to customize through extensions, is Gnome.
Really the hardest part is going to be installing it, but it’s really not too bad. There are plenty of guides, but it’s use a software to get the downloaded Bazzite file onto a flash drive, boot your laptop from that flash drive, follow the prompts and wait. Don’t try to dual boot (keep part for windows part for Linux). It’s possible, but from how you described yourself, not worth the headache.
I touched on this elsewhere, but seeing your comment here… sort of.
iso image is like a .zip it’s a specific type of file… one that opens into a larger image, namely your entire distro. So you could install windows with an iso file. In order to be useful though, you need to get it onto a flash drive, but not just dragging and dropping. Programs like Rufus, mentioned elsewhere, will take that iso of Bazzite and open it onto the flash drive in a way that the computer will be able to read it later and do something with it.
After you have a working flash drive, you do not boot windows like normal and run the installer from a USB. You’ll have to figure out how to tell your laptop (different but similar for each brand of laptop) to boot from the USB. This usually involves having the USB in the drive, restarting your computer and hitting a specific key to tell it not to boot normally to windows, but instead boot from the flash drive.
I haven’t used Windows in a while and I think there’s also a way to restart windows and tell it to boot from USB as you’re exiting. But that’s what you’ll have to figure out for your specific device. That’ll be true no matter what you end up installing.