The Market icon in the lower right of the display leads to a ton of options.
Expand and Inventory Options
We'll get to the shopping in a minute. First, notice the seventh option: Expand. Click this to see the Expansion interface and decide how you'd like to enlarge your kingdom.
The sixth option is a treasure chest named My Inventory. It's your stuff!! Every material you have collected or made, and every building, plant, animal or feature you have stored is shown here!
The second, third and fifth selections are Buildings, Decorations, and Nature. These are the items you will be buying for your kingdom. The first selection, "Featured," is whatever is on sale, or related to a current limited-time event such as a holiday.
The fourth selection, "Town Square" contains something interesting. In addition to a "Store" selling two characters, the Baron and Maya, the "Town Hall" tab shows Ivy and Old Thomas. The white clickbox in the lower left allows you to choose if you want them wandering around your kingdom layout or not!! They will still appear when they need to assign you a quest - they just won't get in the way.