Website from where you download Android Studio contains all the information required by a developer to start Android application development from zero. I see a featured article on their website '11 Weeks of Android' to learn all the new things,
planned and scheduled[
^].
Suggestions:
1. Go through documentation and try. General best practices and tools to be used by developer are mentioned here:
Android Developers[
^]
2. If you like to learn looking at existing projects, believe
GitHub[
^] repositories would help. Even
CodeProject resources are good.
About making money, there are options like In-App purchases. An answer here by one of the CP member details them:
Selling items in Android Game[
^]
Lastly, learn and share. That would help you overall across. Happy Learning!