how the amoeba get food? how the amoeba function and live in?

The amoeba takes in food with the help of a process called phagocytosis. What happens is that as you know amoeba has no fixed body structure, it can stretch to some extent in any direction. When it senses food, its body stretches in the direction in the form of pseudopodia(Literally, false feet). Surrounds the food and ingests by several enzymes. Then it releases the waste in the process of simple diffusion. This is how it functions.