2.5D Side Scrolling Player Movement

Unity Engine
1

I am creating a very small game, a side scroller.
I have loops that generate the floor tiles and some game elements like starting location cube and end location cube etc.

However, I need some help with the player movement.

I create a cube as my player.

I have to turn my players cube 90 degrees in the Y for this code to work.
I have to use the up / down arrow keys.

// PLAYER CONTROL AND MOVEMENT

var speed = 5.0;
function Update () {
var x = Input.GetAxis("Horizontal") * Time.deltaTime * speed;
var z = Input.GetAxis("Vertical") * Time.deltaTime * speed;
transform.Translate(x, 0, z);
}

How can I adapt this code so I can use the left and right arrow keys to move the player left and right.

If you can show me how to implement a simple jump as well that would be awesome.

Thanks for any help in advance.

2

What does the z dimension have to do with moving along the x dimension?.
I just want to move a cube along the X axis.

VarminTheRat helped me solve this issue with movement.

I am now onto jumping.