If you want to watch the celebs on the red carpet get there appxly 35-40 mins before start time on tix.
Security will prob ask you to "move along" anyway.
Curtain will likely start 15-30 mins late.
As for the performance itself, there really is nothing different from any other perf--perhaps the director will come out on stage during bows, as might the writers in attendance.The "fun" part of opening nite is the party after the perf--and it doesnt sound like you have passes to that--but maybe you could find someone who has extra/s.
ENJOY!!!