Where does one locate a listing/explanation of libraries that have been downloaded from
sources like Adafruit? Examples are one source but not all function are used.
in Library Manager, there is a link 'More Info' for every library. if you downloaded the library elsewhere search for docs there. most libraries have source repository on GitHub and there should be a readme doc at least or you can browse the source code. and companies like Adafruit, Seeedstudio, Espressif have web sites and wikis.