Traveling from US to Europe: what are your recommendations for currency conversion and cell phone/data?

I have a trip planned, but since most of it is inclusive, I only need to worry about currency and cell phone/data for about six days. I have a chip and pin credit card, but my debit card is not chip and pin and I’m not sure if it needs to be. I have an iPhone, and I’m considering buying Euros from a bank before I go. Any suggestions? Thanks!