How to Rotate and move a cube

Create a script called CubeControls.cs and put the following code in it :

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class CubeControls : MonoBehaviour
 {
     public float speed;

     // The point the cube will rotate around
     // They represent the middle point of each 4 bottom edges of the cube
     Vector3 forwardRotationPoint;
     Vector3 backRotationPoint;
     Vector3 leftRotationPoint;
     Vector3 rightRotationPoint;
     Bounds bounds;
     bool rolling;
 
     void Start()
     {
         bounds = GetComponent<MeshRenderer>().bounds;

         // Compute the rotation points
         forwardRotationPoint = new Vector3( 0, -bounds.extents.y, bounds.extents.z );
         backRotationPoint = new Vector3( 0, -bounds.extents.y, -bounds.extents.z );
         leftRotationPoint = new Vector3( -bounds.extents.x, -bounds.extents.y, 0 );
         rightRotationPoint = new Vector3( bounds.extents.x, -bounds.extents.y, 0 );
     }
 
     void Update()
     {
         // Make sure you are not already rolling / moving
         if ( rolling )
             return;
 
         // Rotate around forward point when pressing the up button
         if ( Input.GetKey( "up" ) )
             StartCoroutine( Roll( forwardRotationPoint ) );
         // Rotate around back point when pressing the down button
         else if ( Input.GetKey( "down" ) )
             StartCoroutine( Roll( backRotationPoint ) );
          // Rotate around left point when pressing the left button
         else if ( Input.GetKey( "left" ) )
             StartCoroutine( Roll( leftRotationPoint ) );
         // Rotate around right point when pressing the right button
         else if ( Input.GetKey( "right" ) )
             StartCoroutine( Roll( rightRotationPoint ) );
     }
 
     // Make the cube roll around given rotation point
     private IEnumerator Roll( Vector3 rotationPoint )
     {
         // Compute the real rotation point according to current position
         Vector3 point = transform.position + rotationPoint;

         // Compute an axis to rotate in the correct direction
         Vector3 axis = Vector3.Cross( Vector3.up, rotationPoint ).normalized;
         float angle = 90;
         float a = 0;

         // Prevent the user from rolling since we already are
         rolling = true;
         
         while( angle > 0 )
         {
             // Compute the angle and rotate the cube around the point
             a = Time.deltaTime * speed;
             transform.RotateAround( point, axis, a );

             // Keep track of the remaining angle
             angle -= a;
             yield return null;
         }

         // Adjust the rotation to make sure the cube rotates **exactly** 90°
         transform.RotateAround( point, axis, angle );
 
         // Allow the user to roll in a new direction
         rolling = false;
     }
 }