You'll be fine. Just don't do anything you wouldn't do back home, but that applies to any foreign country.
Although one thing which Jon shouldn't do here which he can do back home is try to drink like he can back home. Polish beer and vodka has been the ruin of many a good man! Jon, remember that Polish beer is usually about 6% (sometimes quite a bit more) and that Polish spirits will be at least 40ml measures (if not more). Oh, and Poles can seriously drink.