If you want to program on the blockchain I would have to suggest JavaScript and Node.js

Learning these two bad boys can get you into pretty much any blockchain.

I just happen to know more Java than anything else and would like to make android apps. A huge percentage of programmers hate Java and call it a dead language. I honestly wouldn't recommend starting there.

I'm not 100% sure what you're asking but every blockchain has it's own API calls. The trick behind blockchain programming in my opinion is to make your programs modular. Separate as much code as you can away from the blockchain. This separate code can then be reused on other blockchains.