Accelerate and Move

I need to make a script for a character so it will accelerate forward and move left and right with the key buttons. I also need him to jump. Please help me.

Attach a Rigidbody component, and use the input class to add relative forces.

var moveAcceleration = 20; //rate of acceleration from arrow keys
var jumpForce = 400;  //force at which the player jumps
var height = .7; //distance from the players's main position to its feet

function Update(){

    //forward/back control
    //left/right control
    //use raycasting to make sur eyou are on the ground before jumping
    if(Input.GetButtonDown("Jump") && Physics.Raycast(transform.position, Vector3.down,height)){

you could use the third person controller that comes with unity and you also have to go to edit/project settings/input to set up your keys