They are offering a Manderian class at school. This will be free of charge and get me a minor in Chinese language after 2 years. How could this benefit me?

Yeah it is, but how would that work? It's just an interesting idea. 

Impress women?

My Japanese teacher from high school said Japanese helped him a lot since he worked as a translator for American and Japanese fishermen. Netted him (pun intended) $35 an hour for his first job

If china ever invades the mainland US which is quite likely over the next two to three decades, I'm sure knowing some mandarin would come in handy, no matter which side you came down on.

Chinese is gonna be pretty useful in a few years. 2 years of study should be enough to plead for your life in front of your new overlords.