1. Tap and hold on the desired building to bring up the building's menu.

2. You will then be able to (depending on the item) move, sell, rotate or store the item.
You can move the building by holding your finger on the item and then dragging across with your finger. When the item does not show a red color, you can tap the green checkmark button to confirm its new placement/location. Please note that some buildings cannot be moved, sold or stored. This is intentional behavior