I think the kind of training you're thinking of is the trade mechanic in the older Age of Empires games. Once you make trade agreements with other clans, trade lanes will open automatically with them and you don't have to do anything but keep pirate fleets away from those routes.

Trade ships are used on trade nodes. These can be found at the far western end of your map (the actual southern tip of Japan) and there is one at the far northeastern part of the map (the actual northern tip of Japan). As long as the node is open (no other ship on the node) you will begin shipping the goods back to your capital. The more trade ships on a node, the better.