It depends on the size of the ship and where you sail. And there are cruises, like the ones my wife and I did, that enables you to visit countries you’ve never been to…
We did a Caribbean cruise for our honeymoon. Young wifey hated it even after getting sea sickness shots from the ships' very busy doctor.
A nice "beginners" cruise we took with the kids went out of New York Harbor, up the east coast to Nova Scotia and down the St Lawrence River to Quebec City and Montreal where we got off. I liked that it was always close to land.