Jen-Jon-Freya

Hi guys, wondering if anyone can help! We're looking to book a cruise in a few weeks, it will likely be some kind of central Mediterranean with Royal Caribbean. We have done a smililar cruise twice on the NCL EPic - once as a couple and once with a 1 year old. My question is how do you travel from the ship to the ports of call, in some cases a good few hours to say Rome with a toddler? Last time we hired a car and bought a car seat with us. I know some destinations are accessible by train too. Can you book with the ships tours? Would they be able to take a car seat on the coach? Would a private transfer company take your car seat and store it for the day? Any other suggestions would be great! Thanks