Why is my engine overheating?

I have a 2001 chevy malibu. I just replaced the head gasket. I drove it for the first time and I could smell coolant burning. When I got home I could hear the coolant boiling. I checked the level and it was real low. Plus my car went past the halfway mark on the tempture gage. What could be wrong with my car

I am not sure what was detailed in head job. I had a complete head job. Whatever that details and it was done at a machine shop.

Engine Cooling problem
2000 Chevy Malibu 6 cyl Front Wheel Drive Automatic

i have replaced the thermostat, water pump and flushed the radiator. What am I doing wrong

The coolant light stays on no matter what also the engine light is doing the same. When I add coolant to my car it remains at a decent level until steam begins to come from my coolant tank (reservoir) and it overheats again.

I have had the thermostat replaced. And yes it overheats when I'm driving on the freeway and in the neighborhood. For the engine light. I took my car to AutoZone and they gave me a list of things that could be triggering he light to come on. How I do check the computer? Oh yeah the trouble codes.

Yes I do. Also I got the water pump replaced.

Intake air temperature was one trouble code.
And cylinder misfire detected-cylinder and those were the only 2.

Well. I can put the water in the coolant tank, for beginners lol and the other things. Well I don't know too much about cars and this is my first one, so I am still trying to understand everything.

I have a 2001 Chevy Malibu with approx. 125k miles on it. I've owned the car for a year and have replaced the Battery, Intake manifold gasket, Water pump, thermostat x2, and have had 2 coolant flushes done on the vehicle. I have also regularly changed oil 3 times since i've owned it using mobil 5000 oil or Penzoil High Mileage oil, and a Purolator Pure one Filter each time. I now deliver pizza for a living and my car regularly over heats. The temp gauge will go red and the light comes on. I am possitive it is not the thermostat, and I know it is not leaking fluid. The air valve has been regularly checked and bled. I don't know if the fans are going on/off properly when it is being driven on the road and I would love to know what I need to do to fix this problem as cheaply as possible. I don't make a lot of money and I can't afford high repair costs. I've already put in over 1500 dollars into the car.

The pressure cap is built onto the reservoir and has no way of coming loose. The heat does not come out of the vents as if the thermostat were stuck but I have had the thermostat replaced within the last 2 weeks. There has to be some kind of flow issue with the coolant but I have no Idea how to fix the problem.

What kind of coolant you used? Chev recommends to use Dex-cool (orange color) coolant only for chev malibu to prevent over-heating.