You can find a lot of useful and interesting things in the Shop. It becomes available at some point in the game, so don't worry if you don't have it yet. To go shopping, move to the camp and tap the icon with a trowel and a brick wall in the lower-left.

 

You will see a Shop menu divided into several departments:

 

Not all items and buildings in the game can be purchased, some of them will become available when passing the storyline. Use the Help menu to find what you need or contact our Support team if you can't find something.