From there, you can take Bus #1 "Stazione" to the train station. The bus ride is about 5 minutes. From there you can take the train to Florence, Lucca and/or Pisa.
Getting to Florence by train: Doing it by yourself usually cost less than an organized tour, and you will have a few hours in Florence, but make sure you get back in time for the ship's departure. The cruise lines organized excursion is another option. If the tour gets delayed getting back. The ship will usually wait.
In our opinion Pisa and Lucca are not as far as Florence, and you can do things more leisurely.