That being said there are many venues one could go about learning how to code, but it seems that Google has decided to release an official guide on coding Android apps. We should point out that this guide is not really a guide on actual coding and it doesn’t teach your programming languages.
Instead the guide will teach developers how to publish their apps on Google Play, how to build quality apps, understand Google’s guidelines and policies, how to engage your users and retain them, how to monetize your apps, how to make it more discoverable/reachable, and so on. So if you’re a budding developer trying to figure it out for yourself, perhaps Google’s guide could point you in the right direction.
The PDF is a free download and is about 80-pages long, so you should be able to comb through it in no time at all. Google also has a few printed copies on hand that they are more than happy to send to developers in the US or UK, but they note that they only have a few available so you best be quick about it!