Guys i have howker lvl 1- 2 Cotton sails , 1 double hammocks i have like that fleet
İ am usually in prote

i want to setup trade route but i didnt understand how can i earn money ?

Thx

Setup Trade Route -> Set the port target. Two at least (Port 1, Port 2) -> Don't change the "Select Load policy" or select "Buy only from market - Never empty warehouse" -> The trade fleet will travel from Port 1 to port 2. Unless they sell same item (ex. Tortuga - Vaasburg) the load from port 1 will be sold and items from port 2 will be bought ->
The fleet travel to Port 1 (if you wish to have 2 ports only for your trade route), sell loads from port 2 and buy good from port 1 -> The fleet travel to port 2 and so on... You gain gold! Automatically.

For example you are in Prote, then after you setup a trade route between Prote and Caspian , the Howker will buy 60 crates of wood ( which will be around 6 gold coins for every crate in Prote, but it changes, then 60 crates means 360 gold coins )and then take some time to reach Caspian and then sell it there in which the sold price would be greater than the price of Prote(because Prote sells wood but Caspian sells Cotton , so what you are basically doing is buying in a port where there is abundant of wood and selling it in Caspian which only buys wood ). You will probably sell it for 8 gold coins per crate which is 480 gold coins in total..

So first you bought for 360 gold and sold it for 480 gold which means you got 120 gold coins as profit !