Meteora is certainly not the place for extreme nightlife, as it is mostly a spiritual place. You will find some nice cafes in Kalambaka that turn into bars in the evening, but their music is soft and lounge, not the loud music of clubs. These bars are found in the central square and the streets of Kalambaka. For a bit louder music, go to Trikala, a lovely town about 30 min drive from Kalambaka, where you will find many lively bars along the paved Asklepiou street. Alternatively, you can enjoy a long dinner in the taverns of Kalambaka that offer delicious meat dishes.