The dining rooms serve the same meals. Thedy are just divided up by times of serving. Tables range in size from four to 12 people but most are meant for six with very few of the very large tables. A large table lets you meet more people and have some dinner companions that you will probably get along with very well.
The porters where you drop off your bags will have your cabin # and the proper tags if yours are not on your documents. Make sure you tip them for helping you.
I am not familiar with the ports but it just depends on what you wish to do. If the tour is long you may wish to join the ships tours in order to make sure you get back in time. If you are just going around town usually on your own is much better. Just watch the time and be back EARLY.
Do take in all the shows you can including the late night ones. There is lots of dancing you can do or lounges you can hang our in. Many enjoy the Paino bar. Deck activities are fun to either watch or join in. You are able to do what you want to do with no pressure.