Acts one and two are both set in someone's place of residence; act one is in Parris's house above the parish, and act two is in the Proctor household. In that sense, the setting is similar. They also are the scenes of various relationship strifes; in act one, Parris and Abigail fight, along with Abigail and her friends, and Abigail and Proctor, and then Proctor fighting with Parris and other assorted townsfolk--so, a lot of fighting goes on. In act two, John and Elizabeth fight a bit, and we see further conflict in their relationship. Mary Warren and Proctor fight, and then Proctor fights with the deputies that try to arrest Elizabeth and take her away. Another similarity between the scenes is that Reverend Hale is there, questioning people and trying to hunt down witchcraft--in act one, he questions Tituba, in act two, he questions the Proctors. One other comparison that can be made is that in both these acts, we see how the accusations start and get quite out of hand. As soon as Tituba is "off the hook" for "confessing" to be a witch, Abby and all of her friends jump on the bandwagon, and it spirals out of control. In act two, we see just how far out of control they have gotten. Both acts are very tense, anxious, contentious, and dramatic in their moods.
Some differences between the acts are that in act two, it starts off as a civil, if awkward conversation between husband and wife, that soon spirals into an argument and full expressions of bitterness and mistrust. However, we get to see a bit more of how the everyday functioning of their household works, and them at least trying to patch things up at the beginning. So the setting in act two at least starts off not being quite as dramatic; it is more personal and intimate. As Reverend Hale questions the couple the conversation is more logical and sound than that of the questioning occurring of Tituba in act one. Tituba's questioning was harried, rushed, forced, dramatic and intense.
Those are just some similarities and differences, and I hope that they help to get you thinking. Good luck!