Catch a battle pet.
Great work so far, <name>! You are going to be a pro at this pet stuff before you know it. Now it's time to catch a pet of your own!
Head back out and find a battle pet to fight, engage it in battle, and throw your trap once it's low on health. Bring your catch back for me to see once you are finished.
Remember, you need at least one pet at level 3 to use your trap!