I friend of mine has a huge outdoor barbq/pig roast every year (200+ people). I'm going to photograph the event this year, im not being paid and he didn't ask, but he'll be happy to get good shots of his party. I'm going to use the opportunity to practice on events and hopefully nab some new clients.
Concerns:
one its during the day, not much shade, most likely harsh sun.
not a very scenic location, in fact not scenic at all.
drunk people, lots of them, but i know most of them 
any tips? also which lens should i use? thinking about the 50 almost exclusively...

