Check out example codes for "movement script c#". It will help you in understanding the concepts better.

Code Example 1

private float speed = 2.0f;
public GameObject character;

void Update () {

	if (Input.GetKey(KeyCode.RightArrow)){
		transform.position += Vector3.right * speed * Time.deltaTime;
	}
	if (Input.GetKey(KeyCode.LeftArrow)){
		transform.position += Vector3.left * speed * Time.deltaTime;
	}
	if (Input.GetKey(KeyCode.UpArrow)){
		transform.position += Vector3.up*speed* Time.deltaTime;
	}forward;
	if (Input.GetKey(KeyCode.DownArrow)){
		transform.position += Vector3.down *speed * Time.deltaTime;
	}
}

Code Example 2

using UnityEngine;
using System.Collections;

// This script moves the character controller forward
// and sideways based on the arrow keys.
// It also jumps when pressing space.
// Make sure to attach a character controller to the same game object.
// It is recommended that you make only one call to Move or SimpleMove per frame.

public class ExampleClass : MonoBehaviour
{
    CharacterController characterController;

    public float speed = 6.0f;
    public float jumpSpeed = 8.0f;
    public float gravity = 20.0f;

    private Vector3 moveDirection = Vector3.zero;

    void Start()
    {
        characterController = GetComponent<CharacterController>();
    }

    void Update()
    {
        if (characterController.isGrounded)
        {
            // We are grounded, so recalculate
            // move direction directly from axes

            moveDirection = new Vector3(Input.GetAxis("Horizontal"), 0.0f, Input.GetAxis("Vertical"));
            moveDirection *= speed;

            if (Input.GetButton("Jump"))
            {
                moveDirection.y = jumpSpeed;
            }
        }

        // Apply gravity. Gravity is multiplied by deltaTime twice (once here, and once below
        // when the moveDirection is multiplied by deltaTime). This is because gravity should be applied
        // as an acceleration (ms^-2)
        moveDirection.y -= gravity * Time.deltaTime;

        // Move the controller
        characterController.Move(moveDirection * Time.deltaTime);
    }
}

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