Well I'd say the best thing to do is to start simple. It may sound like the boring way to get going but you'll learn a lot by writing small compartmentalized bits of code than diving into such a large project. One of the most common problems with projects that you're not getting paid for is finding the motivation to finish them. If you create small bits of functionality you'll be able to see how far along you're getting. And if you think about the design of each bit of functionality before you start typing away you'll be able to plug them together to start your game going.
I'd recommend doing something like getting a sprite (image) on screen that can be moved around first. Then try making it "jump" when a button or key is pressed. Once you've got this mastered you could start adding inertia and physics to it, or if you fancy a break leave that bit alone for the moment and start creating life gauges that are displayed on the top of the screen and that you can show being depleted.
If you're new to programming in general then perhaps a gaming framework would be the best place to get started. There are quite a few around and you'll see much faster progress albeit trading in complete control.
Good luck