Problem with moving around

I followed the tutorial for moving a cube but when it is all set up and done and I press play It shows the cube in the middle. When I use the left and right arrow keys it rotates me Revolving around the cube. When I move forward and backward it moves forward and backward but when I is my right and left arrow keys and rotate, and then try to move forward and backward I just move side to side as if I am stuck on a rail. Its as if I am stuck on a rail and cant de attach myself from it. Anyone know what I did wrong?

try this i hope this help :slight_smile: