Hard to answer without knowing what else you've done. Assuming you're fresh into the computer science world, you could try taking the HTML beginners course on C

Hard to answer without knowing what else you've done. Assuming you're fresh into the computer science world, you could try taking the HTML beginners course on Code Academy. After that, choose a language or platform and run with it. Treehouse has a good (I assume) beginners course on iOS development.