Answer:
APA means the American Psychological Association (this is a style guide)
MLA means the Modern Language Association
Hope this helps and good luck with your assignment.
You want a good outline to start... I'd narrow in on the meaning of anti-hero as my main point. Since Satan is the main focus of this question, he should be the main focus of your essay. For an interesting twist, compare Milton's portrayal with Biblical and contemporary portrayals of Satan.