I drank too much Coca-Cola when I was young...what might happen as a result?

Well Coca-Cola has a lot of sugar in it so I'm guessing you had a lot of energy at that age. You are most likely to get bad teeth because of the sugar, so this means lots of trips to the dentist and fillings and maybe even teeth being removed. But you might still be able to avoid this, eat healthy and drink non acid drinks, so water.