Between the end of Act One and the beginning of Act Two, eight days go by. Clearly a great deal happens during this gap because the accusations of witchcraft go from being a relatively private affair—taking place within the home of the minister, the Reverend Parris—to a very public affair, with a bona fide court headed up by various magistrates and the deputy governor of the Massachusetts Bay Colony.
You could write quite a bit here, including a description of the arrival of Deputy Governor Danforth and his introduction to the Reverend Parris (who is so keen to be on the man's good side, as we see in Act Three). You could also write about the involvement of Mr. Hale in setting up the court and parsing through the accusations (especially since he, in Act Four, reveals how responsible he feels for all that happens to the innocent who are convicted). You could even write about how and why Danforth and the other magistrates decide that it is the "voice of Heaven . . . speaking through" the girls who make all the accusations. By assessing the personality traits revealed in the later acts, you can show how these characters got their start in Salem.