Complete beginner question

I am trying to learn .net for AutoCAD but it seems before I can even look at the language, I have to set up Visual Studio.

I have followed tutorials online, but they all are using a much earlier version of Visual Express than what I could get my hands on.

I have followed everything I can so far, but for some reason, some commands that are used don't work.

Namely . It is just black text in the window and always causes a debug error as its not recognised. I have also downloaded and referenced the ObjectARX SDK files but still doesn't work.

Does anybody know why this command isn't being recognised?

This is what I have so far:

Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.EditorInput
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.Geometry

Public Class Class1
   <CommandMethod("HelloWorld")>
   Public Sub HelloWorld()
       Dim ed As Editor = Application.DocumentManager.MdiActiveDocument.Editor
       ed.WriteMessage("HelloWorld")

   End Sub

End Class