Overheating/Check Engine Light

What is your question?

Hi, I went to get an oil change the other day and the serviceman said I was missing 1.qt of oil. I went home and put in the synthetic oil that I had. Everything was fine, until I came back from a trip. I started driving yesterday and pulled over to get my sister stuff and then while my car was on the coolant started to leak out underneath the car ( the car started to smoke and it looked like it was just burning coolant?). The car started to overheat after that, I then pulled over and put more coolant in. The car continued to heat up and the coolant started to bubble when I checked the lid. It happened one more time that day until I refilled all of the coolant. Everything was fine until the car started to overheat (no smoke yet) and then the cars check engine light turned on after 5 minutes of driving. I picked up my girlfriend and pulled over and then waited for it to cool down. Then after 10-20 minutes I started it up and it was fine for about 5-10 minutes in which it did it again. Luckily I was close to home so I just went home and parked my car. I've heard from 3 different people 3 different things. The previous owner: It needs an oil change source/credibility: previous owner/but no mechanic skills. Friend in Auto Mechanical school: It's the thermostat or the coolant reservoir. Source/credibility: Going to school for it/ and teachers advise that the problem over the phone. Neighbor/dad: It's the water pump. Source/Credibility: previous mechanics and plane mechanic. Myself: It's probably it not having an oil change in 2000+ miles despite being filled up with new oil which is causing the engine to overheat and thus burning through the coolant as such. Source/Credibility: Electrical Engineering student intuition (not much).