Common intoductory paragraph for Lysistrata.
Your introductory paragraph will depend on your main idea or thesis. There are several things you could target with this piece--male vs. female, love, war, the use of sex as a weapon.
Choose an aspect of literature to write about--one of the above themes, the use of imagery, or symbol, etc.
Once you have figured out what you want to say about the play, you then will need to support what you're saying with a minimum of three reasons you believe your thesis to be true. You'll want to support all of this with examples from the play to help illustrate your points.