At the meeting, I said "Great, now I can't think of a plot" and intrepid playwright Becky Bruhn said to me: "don't think 'plot' - think character and conflict." And I rolled my eyes at her.
I have better* advice: start your play by typing "THE END." It may be the only thing you write for hours and yet you will still feel like you accomplished something.
*(here, better = dubious)