Creating my first android app help

Hello! so im new to android development and Im going to create a wallpaper app as my first project because that, thats what I feel will on my feet to begin with, I've made a few wallpaper apps for the PC working with C# and the .NET Framework but im not sure the same concepts work for Android Developent so my question is.

When creating a wallpaper app: do I need / what API would I want
for creating a wallpaper app?

Also if you have any links on starting a wallpaper app it would be great because at the moment im just trying random thing and hoping it works.

I think I posted in the wrong section before so im trying to move it over here, but then again, this might be the wrong section.