The “!!! WARNINGS!!!” warning/error is due to a recent change in the Microsoft C/C++ extension, and will be rectified in an update that’ll probably be coming next week. It can be safely ignored for now.
As far as the path/not found errors, I’m not sure what’s going on there. I’m not having any issues with esp32 compiling or intellisense on my linux OS… (Ubuntu also)… I think I did have an issue with Arduino.h not being found at one point, but probably just killed the .platformio folder off and made platformio reinstall itself anew.