My advice to you is this: if this is not a passion of yours, drop this out of all thought and mind. This is an extremely arduous task that will take years before you see any major fruition in your goals. I am not saying that it is not worth it, because I think that it is. But if you are not committed 125% to learning this art, there is no reason to even start.
If you are serious about this though, I would suggest starting with Blender 3D. It is a free, community driven 3d program that is extremely powerful and capable of producing jaw dropping animations. If you are not familiar with it, a lot of this community use it to create the 3D models to import into Pepakura. Last year, the Blender community came together and produced Sintel, an animated short that showcased the capabilities of the engine. I am not a fan of the whole concept/story, but the animation is breath taking. See it here.
If you are interested, let me know. I can walk you through some of the processes that will make your initial start much easier.