how to rotate object unity

Vector3 mousePos = Input.mousePosition;
        mousePos = Camera.main.ScreenToWorldPoint(mousePos);
        Vector2 direction = new Vector2(mousePos.x - transform.position.x, mousePos.y - transform.position.y);
        transform.up = direction;

var rotationVector = transform.rotation.eulerAngles;
rotationVector.z = 0;  //this number is the degree of rotation around Z Axis
transform.rotation = Quaternion.Euler(rotationVector);
//if you put this in a coroutine and yielding for some amount of time 
//you can have something like a rotating loading icon

using UnityEngine;//Attach this script to a GameObject to rotate around the target position.
public class Example : MonoBehaviour
{
    private Vector3 target = new Vector3(5.0f, 0.0f, 0.0f);    void Update()
    {
        // Spin the object around the world origin at 20 degrees/second.
        transform.RotateAround(target, Vector3.up, 30 * Time.deltaTime);
    }
}

//This is how you rotate your player left and rigth with the wrrow keys:

public class Test : MonoBehaviour 
{
	public float RotateSpeed = 30f;
   
    void Update () 
    {
        if (Input.GetKey(KeyCode.LeftArrow))
            transform.Rotate(-Vector3.up * RotateSpeed * Time.deltaTime);
        else if (Input.GetKey(KeyCode.RightArrow))
            transform.Rotate(Vector3.up * RotateSpeed * Time.deltaTime);
    }
}

public Transform Position; // make reference in inspector

Position.Rotate(x, y, z);

Quaternion.RotateTowards(Quaternion from, Quaternion to, float maxDegreesDelta);

using UnityEngine;// Transform.Rotate example
//
// This script creates two different cubes: one red which is rotated using Space.Self; one green which is rotated using Space.World.
// Add it onto any GameObject in a scene and hit play to see it run. The rotation is controlled using xAngle, yAngle and zAngle, modifiable on the inspector.public class ExampleScript : MonoBehaviour
{
    public float xAngle, yAngle, zAngle;    private GameObject cube1, cube2;    void Awake()
    {
        cube1 = GameObject.CreatePrimitive(PrimitiveType.Cube);
        cube1.transform.position = new Vector3(0.75f, 0.0f, 0.0f);
        cube1.transform.Rotate(90.0f, 0.0f, 0.0f, Space.Self);
        cube1.GetComponent<Renderer>().material.color = Color.red;
        cube1.name = "Self";        cube2 = GameObject.CreatePrimitive(PrimitiveType.Cube);
        cube2.transform.position = new Vector3(-0.75f, 0.0f, 0.0f);
        cube2.transform.Rotate(90.0f, 0.0f, 0.0f, Space.World);
        cube2.GetComponent<Renderer>().material.color = Color.green;
        cube2.name = "World";
    }    void Update()
    {
        cube1.transform.Rotate(xAngle, yAngle, zAngle, Space.Self);
        cube2.transform.Rotate(xAngle, yAngle, zAngle, Space.World);
    }
}

 private float desiredRot;     public float rotSpeed = 250;     public float damping = 10;      private void OnEnable() {         desiredRot = transform.eulerAngles.z;     }      private void Update() {         if (Input.GetMouseButton(0)) {              if (Input.mousePosition.x > Screen.width / 2) desiredRot -= rotSpeed * Time.deltaTime;              else desiredRot += rotSpeed * Time.deltaTime;          }          var desiredRotQ = Quaternion.Euler(transform.eulerAngles.x, transform.eulerAngles.y, desiredRot);         transform.rotation = Quaternion.Lerp(transform.rotation, desiredRotQ, Time.deltaTime * damping);     }