The problem is that h is not a String, it's an array of Strings. An array is basically a set of "things" stored together. So you could have int[] a = new int[2]; and that would look like this:
Code:
 ___  ___
|   ||   |
|   ||   |
 ---  ---
  0    1
The above diagram shows 2 boxes (i.e. an array of two items). To access box one, you would type a[0], and to access box two you would type a[1], so what you need to do in your program is:

Code:
public class FirstClass
{
	public static void main(String h[])
	{
		System.out.println(h[0]); // this accesses the first string stored in h
					  // i.e. the first command line parameter
	}
}

/* so if you type:
java FirstClass one

you would get:
One
as output because one is the first command line parameter after the program name*/
I would advise you to look up arrays on the internet (java arrays specifically) if you didn't understand what I wrote above. Good luck,

Adam