What Plato (Socrates) seem to be saying about moral conduct

What does Plato (Socrates) seem to be saying about moral conduct? Give some examples.
What are the three positions represented by Cephalus, Polemarchus, and Thrasymachus?
How does he maintain that “it is never Just to harm anyone?( p.6 )
List & discuss some of the reasons given by Thrasymachus in support of his position that injustice is better than justice? Explain (p.11-14)
What is Socrates’ point about crafts, advantage, and function? (p.10-13)