I don't know if monorail is hte quickest way to get there. If you ave to wait for the monorail, it could be up to a 20 minute wait, then a transfer at TTC then into the park. i would allow at least an hour to just get to the MK, then more time to get in and grab a spot
It might be faster to head over through the international gateway and grab a mk bus. takes you directly there. I would still allow an hour though just to get to the MK
hope your first night pans out!