If I purchased a ticket online from groupon can i just bring my voucher on my phone and that's all I'll need to get in?

They have scanners for that purpose. We had tickets in emal. Ensure you get a stamp at the exit for re-entry.

thanks a bunch Eric!

Reception on site can be hit or miss, I strongly recommend you print hard copies of your vouchers

Yes! Be sure to show up early for the opening ceremony!