Check out example codes for "unity wasd movement". It will help you in understanding the concepts better.

Code Example 1

using UnityEngine;

public class Example : MonoBehaviour
{
    public int speed;

    // Update is called once per frame
    void FixedUpdate()
    {
        Vector3 Movement = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));

        this.transform.position += Movement * speed * Time.deltaTime;
    }
}

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