Here is a list of a few things I have come up with that I feel you should either know or keep in mind when starting to learn android development:
1.) Prior knowledge of object oriented programming especially Java is extremely helpful.
2.) A working understanding of XML is useful.
3.) Get familiar with the Integrated Development Environment (IDE) you plan on using to develop for me personally I going to use Android Studio.
4. Learning a new skill takes time and patience.
5. You will make mistakes but don’t worry you will learn from them.
6 Lastly have fun!