There are 2 ways that could go, based on which theory of physics is correct.
1). If the “Many Worlds Interpretation” of quantum physics is true, you will have created a new branch of the universe / a new alternate history. You can never return to this branch we all live in. But we’ll wonder where you went to and miss you on the board. When you return to the year 2015, your young self will now be rich. So the question is, how are you planning to play this? Will your other self be so grateful that he shares his wealth with you, treats you like a "twin"? What if he resents your presence, or what if money has turned him hard and selfish? You know, you could just play it in disguise when you go back in time, so he doesn’t know it’s you. Then when you come back to 2015 you kill him, and assume his identity (it’s legally your identity anyway! ). There’s no reason for there to be 2 of you. You’re killing an identity that you created by forcing a new branching of the universe. So doesn’t that allow you to ‘play God’ with it?
2). MWI is not correct, either the Copenhagen or Transactional interpretation is correct instead, and the universe we live in does not split. Then physics says there is only one history, and it can’t be altered. Time travel is possible, but you can only take part in events as they occurred, IE, whatever history you visit, you were always in it. If you invent a time machine in 10 years, you could certainly attempt to visit your young self. If you succeed, it’s already happened: If you can recall a mysterious stranger ever coming to see you or your family, maybe wearing dark glasses or a thick beard, that could have been you. You recall anybody ever trying to get you to invest in Apple or Ebay? But at rate, you will fail in changing history. History within any one timeline is unchangeable. You might end up going and trying to stop the JFK assassination, but even with full knowledge of everything that will occur, we know that for some reason or another you’ll fail. You already have failed -- it just hasn't yet occurred in your personal timeline.