Seat yourself, first come, first serve. The CM's are there to keep thing orderly, but you can sit anywhere you can find a seat. My best pick in Mezanine, either the very last row, or the one if front of that. You are up high enough so that nobody's head is in front of you and you can look down on the stage and see everything. When the flying carpet comes out, it's right in front of you and framed perfectly by the top balcony are mezzanine railing. Best seats in the house. On the ground, you can't see the special lighting on the stage floor and everybody's feet are cut off from viewing. The balcony is way to high and you have to strain to see anything below. Mezzanine is the perfect height.
If you're going during a noncrowded time, which your date will probably be, they often don't even open the mezzanine or balcony levels. And if they do, they do it after the the first level is full. Then, even if you came earlier, you could end up with worse seats than those that came later--back lower level compared to front of mezzanine. In such a case, I've never tried getting out of line to get in the new line but it may be worth it.
Does anyone else have advice about that?
We were there yesterday (Sunday) at about 30 minutes to showtime. They were still filling the orchestra line, and we opted to wait nearby until they opened the mezzanine line. Got great seats -- front row mezzanine.
Theoretically I don't think there would be any problem with leaving the orchestra level to get in the mezzanine or balcony lines, you just ask a CM to let you out, and then go back in line. Haven't tried it in practice, but yeah, theoretically it seems okay.
I'd ask the CMs to get a feel for what they're expecting to do for your show, and plan accordingly.
It is first come, first serve. But they might allow the guests that need special assistance in first (guests in wheelchairs, etc.), even if you were there earlier. So sometimes it may not be possible to get a front row seat in the Orchestra level, even if you are the first person in line. I'm not sure if they still do it that way, but it might happen.