You need to study core Java before starting to enter into the android platform.
Try to learn core Java by 5 days
Once you learned Code java
Try the below link and learn it by 5 days
In this link they have explained about android development from the very basic things.
They have many tutorial application with perfect explanation. And it will be easy to understand.
Try below link and learn it by 5 days
This blog will be useful to learn material designs and advanced technologies like chat application to do web service etc..
To know about all android application development and android versions update see the below link
Study and workout the below mentioned widgets by 10 days
- Should know completely about RelativeLayout, LinearLayout and should know where to use it.
- RecyclerView (For list and grid).
- Navigation Drawer, and TabLayout.
- Database (Sqlite, Try to use third party libraries ex. Realm).
- Retrofit, Volley, Picasso, Glide, ,Fresco, Butterknife.
- Material Designs.
- Google maps.
- Thread, Handler, Asynchronous task.
- FrameLayout, Table Layout.
- Intent, Types of Intent.
- Broadcast Receiver, Service, Content Provider
That’s it, you can learn Android with in 25 days.