It is suggested that the best currency exchange rate is in your own country. The country of your destination will have an unfavourable for you rate. Therefore I would recommend to check with your local bank and exchange some (not all) money in advance.

Most of shops, hotels, restaurants and other service providers in Europe accept cards. It is better to pay by card on spot. The rate of your local bank will apply.

If you have to withdraw money from your card, make sure you do not opt for conversion at the foreign cash machine. The rate is not the best for you. Better choose an option withdraw without conversion, then the rate of your local bank will apply.