How can I get taller?

Other than a doctor giving growth hormones which is very unlikely you have to live with the cards you were dealt in the gene pool

why not wait until your done growing

Your height is primarily a matter of genetics. If your parents are both short, you aren't going to be tall. A diet with a lot of protein and dairy products might help you grow a couple inches taller than your father (assuming you are male), but you aren't likely to reach 6' 2".