Pattycakes1998

I’m considering a cruise on Royal Caribbean. I’m going to need a phone to keep in touch with work/family. I have no idea how these things work having never traveled outside the U.S. Phone will need service both on the ship and when I’m off ship in Europe. I’m with AT&T. Can you purchase a limited time plan for that use? Would the phone work on the ship? Should I use the ships wi-fi (if they offer it)