To use DirectX, you will also have to use C++. Except you use SharpDX, then you can use C#.
Since you are starting out and not familiar with DirectX, I would suggest that you look into the MonoGame Framework. It is the open source version of XNA. It's C# (not C++). The learning curve of DirectX is quite steep compared to MonoGame. You can get 2D game/app up and running much faster in MonoGame than using DirectX from scratch.