Long story short, while trying to get a broken water heater plug out of the hole I dropped a piece of metal into the actual water heater tank. Is there a way to get it out? Should I worry about it?
Use a magnet. You can purchase one from an auto parts store or Harbor Freight. They come on a telescoping handle so you can move it around in the tank.
The piece of iron probably won't hurt anything but you will get rusty hot water. That will be an issue for dish washing and bathing.