I was given a grayscale LCD screen from an old Nokia phone. I had hear it can be used with an Arduino.
This is true but the normal practice is to get them on a little PCB, which makes them easy to use with Arduino. I have seen a bare display without the board and metal cover, but I don't recall the connection.
If you can see that there are eight conductors, you might try removing the phone connection and soldering fine leads in its place. You might then try the common wiring orders, of which there are at least two.