the tutorials on the unity website are pretty thorough
work through some of the projects on the right side of this page
https://unity3d.com/learn/tutorials/modu...
the videos for the projects are usually done using C#, but the code below them can be set to C# or unityscript (javascript)
and under Topics you start with
Editor
https://unity3d.com/learn/tutorials/modu...
Scripting
https://unity3d.com/learn/tutorials/modu...
2D
https://unity3d.com/learn/tutorials/modu...
it will take time, but you should be able to figure it out easily enough
and there's plenty of C# tutorials on the web
https://answers.yahoo.com/question/index...
Impossible to say if it will be easy or difficult for you, or how long it will take to do anything. You either want to do something or you don't. Just try it and find out . The worst that can happen is that you will learn something.
How much time will it take to make a 2d-platformer games in unity like Braid or the swapper if u have basic understanding of programming?