Check out example codes for "3d movement unity". It will help you in understanding the concepts better.

Code Example 1

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);
    }
}

Code Example 2

using UnityEngine;

public class PlayerMovement : MonoBehaviour
{
    [SerializeField] private float speed = 5.0f;

    private void Update()
    {
        var horizontal = Input.GetAxis("Horizontal");
        var vertical = Input.GetAxis("Vertical");
        transform.Translate(new Vector3(horizontal, 0, vertical) * (speed * Time.deltaTime));
    }
}

Code Example 3

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);
    }
}

Code Example 4

//player must have a rigidbody2D and a box colider
public float moveSpeed = 5f;
    // Start is called before the first frame update
    void Start()
    {
        
    }

    // Update is called once per frame
    void Update()
    {
        Jump();
        Vector3 movement = new Vector3(Input.GetAxis("Horizontal"), 0f, 0f);
        transform.position += movement * Time.deltaTime * moveSpeed;
    }

    void Jump()
    {
        if (Input.GetButtonDown("Jump"))
        {
            gameObject.GetComponent<Rigidbody2D>().AddForce(new Vector2(0f, 5f), ForceMode2D.Impulse);
        }
    }

Code Example 5

public class PlayerMovement : MonoBehaviour
{
    public float moveSpeed;
    public float jumpHeight;

    void Start()
    {
    
    }

    void Update()
    {
        if (Input.GetKeyDown(KeyCode.Space))
        {
            GetComponent<Rigidbody2D>().velocity = new Vector2(GetComponent<Rigidbody2D>().velocity.x, jumpHeight);
        }

        if (Input.GetKey(KeyCode.D))
        {
            GetComponent<Rigidbody2D>().velocity = new Vector2(moveSpeed, 0);
        }

        if (Input.GetKey(KeyCode.A))
        {
            GetComponent<Rigidbody2D>().velocity = new Vector2(-moveSpeed, 0);
        }
    }
}

Code Example 6

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class ThirdPersonMovement : MonoBehaviour
{

   



 public CharacterController controller;
    public Transform cam;


    public float speed = 6f;


    public float turnSmoothTime = 0.1f;
    float turnSmoothVelocity;   




    void Update()
    {

        float horizontal = Input.GetAxisRaw("Horizontal");
        float vertical = Input.GetAxisRaw("Vertical");
        Vector3 direction = new Vector3(horizontal, 0f, vertical).normalized;

        if (direction.magnitude >= 0.1f)
        {

            float targetAngle = Mathf.Atan2(direction.x, direction.z) * Mathf.Rad2Deg + cam.eulerAngles.y;                       
            float angle = Mathf.SmoothDampAngle(transform.eulerAngles.y, targetAngle, ref turnSmoothVelocity, turnSmoothTime);
            transform.rotation = Quaternion.Euler(0f, angle, 0f);

            Vector3 moveDir = Quaternion.Euler(0f, targetAngle, 0f) * Vector3.forward;
            controller.Move(moveDir.normalized * speed * Time.deltaTime);
        
        
        }

    }
}

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