Alright, so get started with a new project. It'll be a Windows Console Application.
Find the "main" block of code. Some refer to this as the entrypoint. This is where the program begins executing.
Within the brackets (the '{' and '}') type out the following. Anything after a "//" is a comment and can be skipped.
string tmpstr = ""; //Declares a new local string variable with the name "tmpstr" and assigns an empty value
Console.WriteLine("Hello, there"); //Writes a line to the console window saying "Hello, there"
Console.WriteLine("What's your name?"); //Writes another line, you should be able to figure this out now
tmpstr = Console.ReadLine(); //Waits for the user to type something and press enter and then assigns it to our string variable "tmpstr"
Console.WriteLine("{0} must be some kinda leet hecker.", tmpstr); //The "{0}" is a filler, our tmpstr will be inserted there. This is a somewhat more advanced topic, but it's not rocket surgery. Our tmpstr becomes a parameter to the WriteLine function, and 0 designates that it's the first parameter we want there. It's about the same as "String.Format()"
Console.ReadLine(); //This is here so that you must press enter before the window will close. After this line we shouldn't be doing anything else, so the process will exit naturally. Without this line, the console window would just flash and close after typing your name.
If you copy/paste this, I recommend removing the comments. I wrote this up outside the IDE and some of them might break into a new line, causing errors.
Everyone has their own style and practices. My naming conventions are extremely unorthodox, and you'll probably see this in later C# posts by me.