Is anyone familiar with cars?

I have an auto question. The past 24 hours we have recieved a lot of rain, and I hadn’t driven my car in something like 36 hours. This morning, when I left for church, my car as really hesitating, but then seemed to run better after I accelerated some. When I got to church, after a 5 minute drive or so, it was still idling roughly. After church i let it warm up more (even though it wasn’t cold out), and initially it seemed to run better. I also noticed that the check engine light was on, but it’s done this before when the gas cap wasn’t closed completely and will go off after I’ve driven it for a bit 3 times or so. I checked the gascap, and it seemed it hadn’t clicked closed all the way, so I opened it and closed it much better. Now, driving down the road, when I tried to accelerate too much, the engine seemed like it was backfiring a bit (although that’s probably too extreme a term for the noise it was making-it wasn’t that loud or intense). It seemed to be having trouble accelerating…Help! Does anybody know if the heavy rain could have contributed to this, or do I have a major problem on my hands?