In the city, you can find Villagers and Merchants to trade items.
The villager is an NPC that will talk with you to say some things. "Did you already get some exotic seeds from the Wild?"
There are 3 types of merchants in the City, the common Merchant, the Blueprints Merchant, and the Potions Merchant.
With the merchants, you can buy items with gold and sold items to get gold too.
This merchant will be sold to you different types of blueprints.
Blueprints can be used to learn different structures to build in your farm.