2004 Toyota Corolla check engine light

I've had my car since brand new, it's high mileage, and no problems till this point. My girlfriend put gas in it and I smelled gas after stopping every time. Now check engine light comes on, I tightened the fuel cap, until it clicked gas smell has stopped but had the codes read, the autoparts store code reader says evaporative emmission control system vent control, or poor electrical connection, or faulty ccv? Vent control solenoid. Or evap line leakage, or pump module failure, or canister faulty, amongst about ten other "suggestions" where do I start? And what am I looking at? And where? Light is still on and every now and then I get a sputter, especially when it's cooler.