I have a curved spine, what should i do?

my dad was looking at my back yesterday and said i will have very bad back problems when i am older, this is because my spine is in the shape of a (S) but not to that exact extent, i play world of warcraft and have decided to stop that because it makes me slouch in my chair and i am trying to walk upright now on. i think my problem is where i am small i have always had my head down and this has caused the spine along with wow. are there any tips or ways to excercise to decrease the curve in my spine or any tips on how to walk correctly?