Laurettashouse

Hello; I have a 2004 Accord with 110k miles that I purchased less than a month ago and have had nothing but problems with since. First there was no thermostat, I installed one and it ran fine for a few days- then it started intermittently overheating. I took it to meineke and did a pressure check on the engine to see what was going on; everything came back fine but I needed a new radiator cap. Purchased one and the car ran great for a few days. For other reasons I had to replace my radiator (kid at orielly's was playing with a hose and snapped it). After that it ran fine for a few days and then it wouldn't start normally- the engine would turn over indefinitely but in order to start I had to press the gas; as soon as it started it would idle and run fine. I had meant to take it to meineke after work and it refused to start. I knew the spark plugs needed replaced so I replaced them; the car had a rough start but after a few seconds idled just fine but a HUGE plume of white smoke was coming from the tailpipe (more than a David Bowie music video). It turned gray for a moment and then went away, but when I accelerated it became white again. I didn't notice a sweet smell, and my oil is lightly colored as I recently changed it- but other than that nothing out of the ordinary. Aside from a head gasket does anyone have an idea as to what it could be? Residual gas from the previous startups maybe? How long would it take gas to dissipate?