You haven't said what sketch you are running or are looking at.
Barrage of error messages?
The included hd44780_pinIO examples should "just work".
The LCDKeypadCheck sketch is quite complex, but that is not a normal sketch. It is a diagnostic sketch.
It isn't meant to be an example of how to use the library.
The hd44780 library hd44780_pinIO class also comes with several other examples including a HelloWorld sketch that shows a minimal example of how to use the library to initialize the LCD and print "Hello, World!".
Have you read the github page for more information?
What about the hd44780 wiki pages?
--- bill