If an alien ship were to land in your backyard and choose you as the earthly representative of humanity, what would you tell them about our world? Would you consider going back with them for a visit?
This is one of those questions that has too many answers (many of them done to death in good, and not so good, SF novels).
How do the aliens select me? What's their basic attitude seem to be? Why do they want a representative of humanity? Even what they look like or seem to find most interesting/surprising/repellent about us may be a key to deciding how I want to approach them.