It will take a few months just to bring yourself up to speed on mouse/keyboard event bindings and how they interact in one specific browser and one operating system let alone all browsers and operating systems and mobile and that's without even thinking about rendering, templating, network operation wrappers, local storage, camera and sound APIs. The list goes on.

I've been doing this since literally IE 5.5 and I'm still learning new stuff all the time. The fact that you think you can learn all this in a few months is hilarious.