why do all of my photos have SO much noise?

I expose my photos correctly. I keep as low an ISO as possible. Usually 100. My shutter speed is 2x my focal length. Why do I constantly have noise in ALL of my photos. Is it my camera? Using a D5600. It happens no matter what lens I use. Every time I zoom in, its not crisp. (EDIT-I am not posting a picture as I continually have posts removed from this sub for posting pics. Guess thats against the rules)