Employment laws for minors are complicated and messy. Employers generally just avoid the issue. Wait a few years and get some more life experience and you’ll be much more hire-able.
You have to be at least 14 for any type of job. But in the vast majority of cases, an actual company will not hire anyone under 18 for legal reasons. Even when you’re 18, your odds won’t be good for a full-time job, and most companies will have you start as an intern or co-op, assuming you’re in school.
If you want to be coding right now, I’d recommend getting together with friends (or others through the Internet) and coming up with your own apps.