Welcome!
Two thoughts for you:
First, Input.GetAxisRaw() returns a float, so it won’t be of any use to you unless you assign its returned value to a variable (or pass it to a method).
Second, when you post code, use code tags (see this post for info on that). They make your code much more readable, like this:
void Update ( )
{
float h = Input.GetAxisRaw("Horizontal");
Debug.Log(h);
}