Before you jump into this essay's introduction, you should outline the body using this thesis. Once you've done the bulk of the work, the introduction need only contain 3-4 sentences:
- a hook (easily written once the essay's core is planned out)
- your thesis - which here actually contains your three categories so you might want to add a sentence
- a seque into the body of your paper (perhaps introducing the ultimate point of your paper as you will see below).
Right now it looks like your three body paragraphs will focus on character traits of Atticus Finch. You might mention THAT somewhere in the intro. Also, you might want to make some final conclusion about these three character traits. What does being "good, respectful, and calm" actually do for Atticus in the novel? Are these the secrets to his success? Are these reasons he is a good father? Are these reasons he is respected?
Finally, I'm going to encourage you to come up with a different adjective in your thesis to replace "good." Most teachers agree that "good," used anywhere in an essay is a bad word. There has to be something more specific you are driving at. Is he a good listener? Or perhaps you are aiming at good hearted? In this case, perhaps you mean to say he is compassionate. At any rate, good is far too common to base an argument on. Consider alternates.