If you want to create apps, you can download the SDK (developer.android.com/sdk/index.html) . It comes with eclipse, which requires Java programming knowledge.
You can also create games (3D/2D). For those I use Unity3D (unity3d.com/unity/download). Programming games in Unity3D requires some math... Think about vectors and quaternions... You can use both .net's programming language called C#, or Java. There's also a third language you can program within Unity, but I won't encourage it (C# and Java are widely used for a lot of other stuff.)
Both Eclipse/Android SDK and Unity3D is free. But understanding enough programming skills to create good running apps requires a lot of time. It took me a year to understand C#/Java and a few months to find my way around the API's. Designing skills are also a must. You can use Photoshop, Illustrator, InDesign, Gimp, or w/e.
To learn programming, there are a lot of tutorials on YouTube or other websites. Don't give up too soon, it's a long but fun road...
Happy coding
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