This question was inspired by my hatred of Temporal Anti-Aliasing which, in many games nowadays, is poorly used as a performance bandaid. On lower resolutions it will smudge and blur the image and certain bad cases of TAA will cause visible ghosting.
Yet in spite of all this, certain games won't let you turn it off or have hair/fur/foliage look like dogshit without it so sometimes I still use it.
Startpage uses Google on the back-end but keeps your searches anonymous. Or there's always DuckDuckGo.
Don't, it's not ready yet unless all you do is call and text. (Then it's fine ig)
Try out a live USB, it won't save anything you do to it and you won't risk deleting your data by accident (like with dual boot). All you need is an old USB stick / flash drive (just make sure it's big enough, a few Gigabytes should be good)
Here's a walkthrough for Linux Mint (an Ubuntu alternative). I'd recommend specifically Mint Cinnamon (Download Link):
https://itsfoss.com/linux-mint-live-usb/