If you haven't started to learn .Net at all then I would recommend C# vs VB.NET
+1
By my side, while learning AutoCAD .NET, I don't think "My first Plugin" is the best tutorial to start with. It deals with the Overrule API which is far to be the simplest one. If you want to try this tutorial with C#, I tried a code conversion to C#
here.
I'd rather start with: "AutoCAD 201X .Net Training" on
this page.
Anyway, before comming into the AutoCAD .NET API, you'll have to learn the .NET basics...