does the north bound Newburyport train stop at Montserrat Station and what are the weekday times

Only the Rockport line stops at Monsterrat. Times can be found online or at the station. Early morning and late night trains will only stop if passengers on the train notify the conductor, or passengers at the station wave down the train.

Always double check before getting on the train, occasionally I've gotten on the wrong train, my bad, but it's always good to check the personnel informed me, especially on the weekend.

No. Rockport trains stop at Montserrat.

Flag stop got wave as it approaches