If you're 13 or so, develop some idea as to how programs are put together, and what might be involved in debugging them. These skills will be applicable to any

If you're 13 or so, develop some idea as to how programs are put together, and what might be involved in debugging them. These skills will be applicable to anything you end up doing. If you have a secondary, non-programming interest, develop that as well and try to think about how computerization/software could impact it.