What position should I play?

You have the physical skills to play QB, but you need the ability to lead the team. You need to be the one who the team can rely on. If you're down 2 TDs or something and your team is dragging ..you have to be the one to pick them up and keep them in the game. With that height I think you should either bulk up and play tight end or work on your route running and catching ability and play some WR. If you're in high school 6'3 is tall enough to where you can snag most jump .