Is there a way to make my flagship (only one I have at the moment), go back and forth to the main Island/city and sell whatever items I have a decent supply of and return with items I need (such as tools)?
How do I make items I have plenty of available for other players/ships to automatically purchase from my port? Do they drop any items off or just collect and pay for? Do you set the price of items or is this all automated?
Absolutely. Click on the star/compass button thing in the bottom right corner of the screen, and it should bring up a map. Where it says "trading routes", create a new one. Then add the two warehouses you want to trade between (your warehouse and the main island one). You can do this by either clicking on them on the map, or using the dropdown box at the side. Then, once they're both added, choose which items you want to go where. If you want to take wood from your island to the main island, sell the wood, and bring tools back, then make it so it says "+Wood -Tools" on your island, and "-Wood +Tools" for the other island. Then add a ship to the trading route and it'll do it's thing. Remember that on the trading screen, each resource icon only represents 1 slot on the ship, so if you want the ship to take 2 lots of wood over, add the wood twice (and make sure to sell it twice).
When things get more demanding later, you'll have to create new routes, add more ships to existing routes, etc. This all applies to trading goods between your own islands as well, except obviously you won't be paying for them.
As for selling things from your warehouse, you'll notice AI ships come to your harbour every now and then. If you click on your warehouse, and at the bottom right of the screen, where there are 3 tabs, choose the bottom one. That will bring up a trading screen, where you can choose what to buy and sell. + is to buy, and - is to sell. When you add a resource, if you then click on it, you can choose how much you want to keep in reserve. If you raise the reserve of rope to, say, 20, you'll always have 20 rope in there, the AI won't buy any more than that. On the same little window where you can raise and lower the reserved goods, if you click the 2nd tab at the top, you can change the price to buy or sell at. Obviously, buying at a higher price will make people more likely to sell goods to you, and selling at a lower price will make people buy more goods off you, but you won't be getting as much money.
I leave the price at the default amount, it seems to work fine. Note that the AI ships that visit your harbour have a set max amount they will spend per trip. I think it starts off at 500 or 1000, but it can be upgraded using your honour. See how much people will pay for goods while still spending their max allowance. For example, you could sell them 20t tools at 50g each for 1000g, or you could sell them 15t tools at 66g each. Obviously the second option is better, as you'll get more money per tool. However if you set the price too high, you might only sell 5t tools at 100g each. While you'll be getting more money per tool, you won't be getting as much money overall. Learn to balance it to match your surplus and needs.
Note that neither ways of trading with the AI are required to obtain a stable late-game economy, but they can help getting a little bit of money early on, especially if starting on a harder difficulty.
. Still, 6k income and loads of raw materials so it shouldn't take too long to get up and running. That's the Master Builder scenario, should get started on the cathedral actually.
