Hi, you can expect approx. 250 VTG singles on that cruise. All ages. Yes, lots of singles go one day early so they can attend the pre-cruise party located at the International Market-Place located on the Biscayne Bay. The cruise ships are located on the other side of Biscayne Bay. You may be able to see ships from your hotel if your room is super high level.
Hotels near by are Holiday Inn, Courtyard Marriot, Hyatt, and some other hotels that I don't remember right now. You can walk to the International Market Place if you book one of those hotels. You should book as soon as possible because the hotels get booked up fast due to having approx. 6 ships in port. Almost every cruise line is there in Miami. lucie