Is DNA more like a recipe book or an architecture blueprint that contains the instructions to make materials needed to build it?
DNA is like a ticker tape that has symbols for amino acids on it, and when a cell puts amino acids together in that order, they fold into proteins.
It looks like a bar code to me and I don't understand how scientists interpret it.
Well, with this:
DNA doesn't look like a "bar code" so I'm not sure what you're talking about. DNA looks white and stringy: