Overheating after new fuel pump

2000 300M: My car overheated a couple of times; when it broke down the 3rd time, the gas was running out really fast and it cut off. After putting gas in it, it still would not drive properly you had to keep pumping the gas pedal non stop. Also after starting it after putting the gas in it, fluid leaked from under the car in the front. I was told later on it needs a fuel pump by several people. I just got one put in today and the fuel line was replaced. On my way home from the shop, mind you I don't live 10 minutes away if that, I noticed the thermostat light came on and that it was approaching hot. I haven't driven the car since October of 2013 and it was basically sitting for that time. What is most likely the problem(s) and about what would it cost me to repair? I've been told by a friend I need to get a new compressor (the doesn't work), but I believe there was another reason given I don't remember though. Also, it's been suggested maybe a new thermostat or radiator...Please help me go in the right direction.