Worlds Arena Rules for leaving and coming back into the building

For group stages (Oct 8), Ill be arriving at the SF airport (coming from Ireland!) at around 4 pm and would still like to watch the games. We bought two tickets for a 1 pm start game.

1. Will my fiance be able to get back into the arena/seat after he has already gone into the place? It's so that he can arrive at the place and watch for a couple of hours then leave to pick me up at the airport. He's already in the Bay, just waiting for me to arrive haha.

2. May I arrive late to the place? Do doors close at 1 pm?

This is my very first time going to a league tournament and I have no idea what the rules are for this kind of thing. :)

Thank you! Antronnus