A couple weeks ago my Pixel XL 2 (or Pixel XL, not sure) started to have black blotches all over the screen. They grow, enlarge and eventually engulf the entire screen. Now except for a sliver on the upper right corner, the screen is pitch black regardless if it is on or off. What kind of damage is this? There had been no physical damage to the phone. As far as I can remember, the phone has never been dropped or otherwise subjected to excessive physical forces.
I am trying to find the phone's IMEI, but I am not sure how to go about doing it without being able to see anything on the screen.
Also when it is plugged in to my laptop via a USB-C cord, my Windows 10 recognizes the phone, but I don't see an additional drive. How should I access the files on there? Is there a way to reset the phone and clear the data?