Crank/no start things to check?

My buddys 2004 cavalier would not start this am. I checked the gas cap, spark plugs and then ran OBD scan and the same code came up twice. P0440 Evaporatiuve Emission Control System, P0442 Evaporative Emission Control System Leak Detected (small leak), I really just need to know the location of it and some "things to check'. MAP, Mass Airflow, fuel presssure regulator, Throttle Position sensor? Idk