learning

Hi i'm confused with learning about plants.  My boss at the garden center told me to look up plant families and learn their common names and their common names aswel as where they like to grow and where they come from.  My mate told to keep it simple and told me to just learn the name of the plant, where it likes to grow and what soil it likes.  That's what he wants to know when he buys plants.   I don't know shall i learn just those three things that my mate told me to learn that a customer would want to know?  i don't want to go scientific.

I would prefer to learn what a customer would want to know about a plant.