It could be various reasons. First of all, make it simple and make sure you have some fuel in the gas tank. If you do and the car won't start it could be the battery, starter, or many other things. I would try to tow the car to the dealer or a local repair shop to get the vehicle checked out. They hopefully can then tell you what is wrong.
The 2007 Ford Fusion has 16 valves.
The 2007 Ford Fusion is a gas-powered vehicle.
The 2007 Ford Fusion has an inline 4 engine.
The 2007 Ford Fusion has a 5-speed manual.
The 2007 Ford Fusion has a drag coefficient of 0.33 Cd.
The 2007 Ford Fusion runs on regular unleaded.
The 2007 Ford Fusion is 15 ft. 10.2 in. (190.2 in.) long.
The height of the 2007 Ford Fusion is 4 ft. 9.2 in. (57.2 in.).
The 2007 Ford Fusion has double overhead cam (DOHC).
The curb weight of the 2007 Ford Fusion is 3101 lbs..
The 2007 Ford Fusion's turning circle is 38.7 ft..
The 2007 Ford Fusion has 37.0 in. of rear leg room.