(FTC) Using FTCLib - cwm9cwm9/TTGT-FTC-FRC GitHub Wiki
You will not find many tutorials for using FTCLib. That is because FTCLib is basically a clone of WPILib and is used in pretty much the same way. Any WPILib tutorial will teach you what you need to know to use FTCLib with the caviat that minor changes are required in the Robot class to deal with differences in Op mode selection and hardware mapping between FTC and FRC.
Entries in the WPILib folder with a (+FTCLib) in the name apply to FTCLib