I should get a picture of it, but the plastic piece that hangs down from underneath the front end of the car, I don't know what it is, but I must have hit something, because the front left corner of it cracked and broke off, I don't know where it is or how important this piece is. I seem them on Impala and Monte Carlos only though...should I be concerned with this?

 

They are called air deflectors. What they do is push air UP into your engine bay to help cool it while you drive. They are extremely important because the front of the car does not really have large openings to let air get in. How much is broken? If it's still functional youll be fine.