Given your comment that this is your first shot at programming, here's something that's either a nit or a crucial distinction:

"type hw to print hello world script!";

As constructed (and, even as corrected by marto), your script will NOT print a script; it will print only the greeting you placed in quotes.

How to actually print a script, self-referentially or otherwise, is something you'll find here with the search or supersearch tools..and a carefully constructed query.