Dreams and illusions are a key theme of the entire play and there are certainly many references to dreams and in particular the tension between dreams and reality. Here are three examples that you could use:
Hermia at the end of Act II scene 2 wakes up having a nightmare of a crawling serpent on her breast. In this sense her dream is actually a prediction of what is to come:
Methought a serpent eat my heart away,
And you sat smiling at his cruel prey.
Of course, Act III scene 2 does show this - Lysander shows complete unconcern about what Hermia suffers when she encounters the perplexing situation of the lovers.
You will also want to look at the end of Act IV scene 1 when Bottom wakes up from his "dream". His soliloquy actually discusses the relationship between dreams and reality as he struggles to make sense of what has happened to him. He talks about how indescribable dreams often are because of their vivid nature, and how dreams are so fantastical that we cannot ever really describe them to do them justice.
Lastly, Puck's soliloquy that ends the play rather humorously suggests to the audience that if they are offended by the action of the play they can pretend it is all a dream, which raises questions about how we as the audience perceive the action and also if pretending it is a dream allows us to forget some of the more pertinent lessons that the play hopes to make: namely what fools we mortals are, especially when we are in love!