When the game starts, you will see the creatures at the current level and the number of foods required to evolve and the number of foods required to evolve on screen.Tap on food and give the creatures the number of foods required for evolution to creatures, and they will evolve.Please note that food is not generated until a certain amount of time has passed, so check the app regularly and let the creatures get more food.It is cleared when the creature evolves to the final form.