Question Why wont unity scripts inherit MonoBehaviour class or call debug.log or any custom made classes?

I'm new to unity, I've created a project, created a new empty game object and attached a script to it, however I'm unable to even call Debug.log, the class is not recognised and I cannot create an object of any classes which I've made in the asset folder, the script won't find either....
can anyone help...

 

okay, solved it, had to follow the steps at
Unity - Manual: Visual Studio C# integration (unity3d.com)