Hello and welcome.
First of all: What’s this directory “sal”?
Have you created it?
From your output it seems that you are in your home directory.
So you’re trying to copy that file into the root ("/") directory into a directory there (“sal”).
There you have no permissions as a normal user.
You could do that with “sudo” in front of the mv command.
But be careful. What are you going to achieve with it? Or is it just for practice?