I typically buy parts and peripherals from Amazon. Newegg can be good for the mail in rebates or discounts that you can get.
I typically don't shop at bestbuy unless I have to but I also live 20 minutes outside of town where I am so thats 40 minutes of driving that I don't wanna do typically.
Keychron was my last keyboard purchase, very happy with it. Full size mechanical keyboard, replaceable switches, so heavy I could probably kill someone with it, good keyboard.
Edit: I'm in the US so didn't think of micro center off the bat, but great option if you have access.
Wasn't a fan of mint when I tried it. IMO, I found popOS to be an overall better experience when I first started using Linux and have since switched back to it after having a few issues on Fedora.
You might give that a shot especially if you are using nivida. PopOS hasn't given me much grief (aside from Gnome but that's more a personal distaste for it)
Even after being on Linux for a year and considering myself a fairly capable guy in tech, Linux is kind of a pain in the ass if you're doing more complicated things like in my case music production.
But it sounds like you've had an even worse go doing normal things which sucks. I feel for you man. I hope your next go is better.
It took me a few tries and Windows being a privacy nightmare to switch. It can be done but it wasn't (and still isnt) easy.