It may take an hour or so to get off the plane, gather up your luggage, and board the bus. The bus won't leave the airport til it's full, so you may be waiting there for a little while. By the time you actually get to the port, you might be able to go ahead and board. I have heard others say they have boarded around 11.30am.
I have never been to this port before, so I don't know about storing your carry-ons while you walk around.
What date are you sailing? We will be sailing 12/9.