What do you think is important: Playing football? Making friends? Getting good grades in RE? Learning about things? Being successful? Getting rich? Becoming famous? Helping others? Doing the right thing?
Your values are whatever interests you and whatever you think is important. The subject of values has concern Philosophers since Philosophy began. As result, Philosophers have spent much time and effort describing values and explaining why they are important in our lives. This branch of Philosophy is called Ethics and you learn about Ethics in our RE lessons. The idea of Justice, the idea of fairness, what is right varies from person to person (is subjective). It changes in time and in cultures. Try to think about the principles of retribution, punishment and forgiveness in the application of Justice.