2004 Dodge Intrepid Car Starting

Computer problem
2004 Dodge Intrepid 6 cyl Automatic 87,000 miles

I have an issue with my Dodge Intrepid. My check engine light is on and I am having problems with starting my car. 9 times out of 10, the car will start fine and run great. However, it will not start once in a while. Sometimes, it will try to turn over and doesn't. Sometimes, it only clicks. I can disconnect my negative battery cable and wait for a few minutes and the car will ususally crack right up. Or you can do nothing and wait for a few minutes or a hour, and the car will crank right up like nothing ever happened. The problem seems to be getting worse. Now I have had it die on me at an intersection while I was stopped at a red light. It started up again but then died 100 yards later when I was pulling into a parking place. I bought the car about 1 year ago with 80,000 and have never owned a Dodge before. With no car history, I am at a loss. I took it to Auto Zone and got 3 different error codes off of it, PO344, PO440 and PO442. I have been told that the camshaft sensor is the issue or it could be a bad fuel cap, EVAP canister or hose is bad, purge or vent solenoid is bad or I have a vacumm leak. I have NOT got the money to take it to a dealership. And computerized cars are over my head. HELP!