Hi Bridget,
Let's start out with some basic checks and try to find out if there's any life in your phone despite a possibly broken screen.
* Do you get any vibration when you (try to) turn it on?
* How about when you plug it into the charger?
* Does the silent switch do anything?
* When you plug it into a computer is it recognized by iTunes?
Give those things a quick check and let us know what you find. There are a lot of smart people on here so I'm sure we can figure out what's going on with your phone.