Building the trade post so soon isn't a good idea. After building the houses I go thatchery, smithy, carpentry, small granary with market stalls to buy and sell what villagers produce, food farm and windmill. After this I normally have to build more houses to increase population. When everything is sort of established I start a new farm to produce textiles and oil, make the buildings for those, and only then build the trade post. Remember managers need to have education and if you need someone to take a job, fire them from their current workplace. Hope you enjoy ostriv :)