What did Reverend Parris do before coming to Salem?no

The answer to this can be found in Miller's notes from Act
I, Scene 1.  They are in the part of the notes that is found before the dialogue
actually begins.

In this part of the notes (in the last
paragraph of notes before Tituba's first line), we are told that Parris was a merchant
before he became a minister.  He pursued this profession in Barbados, which is relevant
because that is where he met Tituba.  He presumably (we are not actually told this)
bought Tituba and then (we are told this next part) brought her with him to Salem from
Barbados.