If your trip is going to involve a fair amount of sightseeing, be sure to prepare in kind. If you are going to be doing a lot of walking, for example, spend time prior to the trip walking and building up your stamina.
Our trip to Italy involved a LOT of walking, and much of it was on slopes and on cobblestone streets and sidewalks (read “more likely to trip or stumble”).
While there were ports that were relatively flat and walking was easy, like Venice, there were some that required steep climbs, like Trieste, and climbing many steps, like the walls of Dubrovnik in Croatia.
If climbing is your thing, then you would enjoy the challenge of 414 steps in the Bell Tower in Florence, or the hours-long walk in the area of Cinque Terre.
Just be sure to go with the level of physical activity in mind. “Train” for the trip!