1. Ensure there is enough food for the animal to feed on. You can do this by getting some wheat, plant them, and wait for them to germinate. You should harvest your wheat after they are grown enough to harvest so as to store feed for your animals.
2. Find a proper location to keep your animals. A fence enclosure would really do, so as to prevent your animals from wandering away.
3. Take your wheat with you, and then go in search of the animal you would like to keep. Immediately the animal sees the wheat in your hands; it will start to follow you. Take the animal to where you have prepared to keep them.
4. Do the same thing in searching for more animals. But ensure you gather the same kind of animal. Note that you should make your cage or enclosure big enough in case you want to keep a large number of animals.