A decent place to start online is at
Sun's Java Tutorial site. But if you truly want to go through the whole process of learning a language by yourself, you gotta be patient. It's tough to start off from zero and dive right in...I did it, but it was way (wayyyy) back on the Apple IIe with Applesoft Basic, much (MUCH!) easier to learn.
Anyway, give it a go, start off with the easy stuff, and don't give up! Good luck!
Another course may be to find an Java/Android programmer near by and see if they want to collaborate with you to help get your ideas going. An hour with someone who knows what they are doing is priceless!