We know most plants make their own food. However, some plants also have other methods of getting food.
Some plants eat insects. They are insectivorous plants. They grow in soil that is poor in minerals. To get the minerals they trap and eat insects. Venus flytrap and pitcher plant are insectivorous plants.
Some plants that are not green. Take a slice of bread. Sprinkle a little water on it and leave it for a few days. After few days the slice of bread changed it color. Something begins to grow on it and the slice is spoilt. Use a lens to see what is growing.
A plant called mould starts growing on the slice. It takes food from the slice. This plant is not green. It does not have chlorophyll and cannot make its own food. Such plants are called fungi. Mushroom is also a fungi. Fungi grow on other plants, on dead animals or plants, or on stale food. They get their food from these.