Hello!

I'm interested in going to the opening ceremony on Thursday. I see I can purchase a ticket online, but I would feel 'safer' doing it in person at the event itself. It starts at 6 pm, so I would go there and be there at maybe 5:30 pm and buy a ticket at the post office itself. Is that possible?

Also, at the opening ceremony, will there be a chance for autographs or photos with the competitors? 

Thanks!