There are spectacles for adults and children, concerts. The problem can be language, bocouse all spectacles are of course in polish... At the front of Theatre there is a place with fountains. Near of it is the park.
The most people dress elegant, but the young people go there often in jeans.
In little town called Hajnowka there were a couple of (but not many) pubs and a small 'nightclub' where you can get into local nightlife. It's a pity that I don't remember names of the places but you will find them - there are not so many of them :)