I want a game object (e.g. a Cube) to be a controllable player where when you press left or right it turns on the Y axis and forward and backward are obvious. Is there any special script i need or is this something relatively simple to do within unity?
Create your object and position it above the plane
Select your object in the hierarchy
From the Component menu select Physics/Character Controller to add a character controller to your object.
From the reference, get the scrip from either of these to links: 1 or SimpleMove and attach them to your object.
Note there are lots of tutorials and other learning resources on the net. You might ramp-up faster if you work through some of these tutorials. Here is one site: