yeah it could go wrong. the same way that the bus you ride to uni could explode, you trip in the shower and get brain damage, or your house catches fire.
generally, if you dont look for violence, it won't come to you.
theres always that off chance of an unprovoked bashing - but seriously, theres gunna be a million kids around you, cops everywhere - unless you look for trouble, you'll be fine.
bad decisions under alcohol? that can happen anywhere, know your limits - and if you're not retarded, then you wont do anything stupid.
just because there is no authority, doesn't mean you have to be stupid and do dangerous things. Again, unless you're an idiot, you'll be fine.
What's wrong with a little risk in the first place?
Do you wanna turn 50, look at yourself - you've got a wife and two kids in a 3 bedroom house in the suburbs and a commodore and be glad that you've taken the safe option? theres so much more to life, and so much fun to be had.
Keep an open mind, enjoy life. when you die its over - you've got an infinite amount of years to be nothing.
Be mature, be smart - and the chances of things going wrong are no different to everyday life.