It was very hazy today, so while I was driving to work, as the sun rose, it looked very red and wasn't very bright.
I noticed a dark spot on the disk of the sun! What was it? A planet or a comet in the way? A sunspot?
First: DO NOT LOOK DIRECTLY AT THE SUN. Even at sunrise or sunset, or if the Sun is partly masked by clouds, it can still be bright enough to damage your vision if you look long enough--and you never know when the clouds will shift. Please don't take chances!
You can view the Sun safely by projecting its image using binoculars, or a pinhole camera. Here is some more about safe sun-viewing techniques
What you saw was a sunspot. There is a particularly large one on the Sun's face now. You can find out more about sunspots, and see which sunspots are visible at SpaceWeather.com