Consider the following as you read Much Ado About Nothing:
Beatrice and Benedick are two of the most complex, fully developed characters in all of Shakespeare's plays. Their complexity stems from their self-awareness; in the midst of mocking their friends and each other, they recognize their own faults.
The play itself is complex because we are given multiple views of these characters. We see Beatrice and Benedick through one another's eyes, and each through his or her own eyes, but we also see them interacting with their friends and families, and we hear these friends and family members talk about them when they are absent.
Also look out for uses and abuses of formal language. While Benedick and his friends seem to be well-born and educated, and can, therefore, make complicated rhetorical jokes and allusions with ease, attempts by Dogberry and Verges to use elevated language fail utterly.