Go into the menu and choose Pet Supplies. If you have bought any food or water/milk, and choose only one at a time. let the dog consume all it wants from the dish before switching to the next time. To buy more supplies or toy, choose to Go Out where there is a store to buy items. But if you don't feel like paying full price, take the dog out for a walk and make a stop at one or both shops, where the prices are lower (but what they have and the price is always changing). Also you might find some stuff lying around when walking and tug on the leash so that the dog will stop to pick it up!