Interesting idea and having read your information about learning coding, a great first attempt. There are some problems with the interface that need sorting in particular loading/unloading cargo. I found it hard to tell what was on the ship.
It would also be good to have a general idea of what goods are in demand where so that you could make a decision on trading routes. Maybe through a Newspaper report - "Gold discovered in Niagara - lumber in huge demand" etc.