I have a question about the tomato sauce. It says to use a 28 oz can or fresh tomatoes. What is the quantity if fresh tomatoes are used?

By weight it would be the same, as in 16 ounces to a pound. Although with canned there is likely to be additional juice added. And you will want to run them through a food mill or food processor. But I wouldn't worry about the precise measurement for this type of sauce as there's not much that can go wrong. In Italy the tomato is added rather sparingly.