You decide whether you are a social enough individual to cope in these situations or not. Can you enjoy yourself when you know few of those there, or are you the sort that sticks there in a corner wondering why you came ? Only you can really answer that.
That said the more you face situations outside your comfort zone the more you reach a stage when they are less of a problem for you.
If you do go then IMO you deal with situations by playing them by ear. Surely you'd just get stressed out working out a tactic for every eventuality.
And recall, whatever you decide, it's only one party in a whole lifetime.