What I do not understand is if that library is supposed to be part of the base IDE install then why do I need to find another one and even if it is part of the IDE or a separate 3rd party one why doesn't the IDE see it?
LiquidCrystal.h is a base Arduino library, but not LiquidCrystal_I2C.h.
I would delete what you have previously installed, and then use the library manager of the IDE to install the library. It will go to the libraries folder with the sketches.