How to get cart item remove or empty (truncate) in magento 2

Company name :- Sbr
Module name :- Checkout
File path :- /app/code/Sbr/Checkout/etc
============= File name events.xml =====================

<?xml version="1.0"?>
<!--
/**
 * @author     SB , SBR
 * @package    Sbr_Checkout
 * @copyright  Copyright (c) 2015 Sbr Limited (http://www.Sbr.co.nz)
 * @license    http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
    <event name="controller_action_predispatch_checkout_cart_add">
        <observer name="beforecart"
                  instance="Sbr\Checkout\Observer\BeforeCart"/>
    </event>
</config>

=================================================

============= File name module.xml =====================
<?xml version="1.0"?>
<!--
/**
 * @author     SB, Sbr
 * @package  
 * @copyright  Copyright (c) 2015 Sbr
 * @license    http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
    <module name="Sbr_Checkout" setup_version="2.0.4">      
    </module>
</config>


======================================================
============= File name BeforeCart.php =====================
File path :- /app/code/Sbr/Checkout/Observer

<?php

namespace Sbr\Checkout\Observer;
/*
ini_set("display_errors", "On");
error_reporting(E_ALL);
*/
use Magento\Framework\Event\ObserverInterface;

class BeforeCart implements ObserverInterface {
   
    protected $cart;
   
    public function __construct(
        \Magento\Checkout\Model\Cart $cart
    ) {
         $this->cart = $cart;
     
    }
   
    public function execute(\Magento\Framework\Event\Observer $observer) {

$_objectManager = \Magento\Framework\App\ObjectManager::getInstance();
$storeManager   =   $_objectManager->get('Magento\Store\Model\StoreManagerInterface');
$currentStore   =   $storeManager->getStore();
$currentStore_id = $currentStore->getId();
if($currentStore_id==1):
$count=count($this->cart->getItems());
if($count>=1){
foreach($this->cart->getItems() as $_item){
$sku=trim($_item['sku']);
if(($sku=='basic1')||($sku=='starter')||($sku=='professional')||($sku=='premium')){
$this->cart->truncate();
}
}
}

endif;
    }

}

=================================================================

==============File name registration.php ========================

File path:- app/code/Sbr/Checkout

<?php

 

\Magento\Framework\Component\ComponentRegistrar::register(

    \Magento\Framework\Component\ComponentRegistrar::MODULE,

    'Sbr_Checkout',

    __DIR__

);

====================================

How to get customer data from email id in magento 2

$bootstrap = Bootstrap::create(BP, $_SERVER);
$objectManager = $bootstrap->getObjectManager();
$customer_email=$_REQUEST['list'];
///echo $customer_email;exit;

$objectManager = \Magento\Framework\App\ObjectManager::getInstance();


    $url = \Magento\Framework\App\ObjectManager::getInstance();
    $storeManager = $url->get('\Magento\Store\Model\StoreManagerInterface');
    $state = $objectManager->get('\Magento\Framework\App\State');
    $state->setAreaCode('frontend');
    $websiteId = $storeManager->getWebsite()->getWebsiteId();
    // Get Store ID
    $store = $storeManager->getStore();
    $storeId = $store->getStoreId();
    $customerFactory = $objectManager->get('\Magento\Customer\Model\CustomerFactory');
    $customer=$customerFactory->create();
    $customer->setWebsiteId($websiteId);
    $customer->loadByEmail($customer_email);// load customer by email address
    //echo $customer->getEntityId();
    //$customer->load('1');// load customer by email address
    $data= $customer->getData();
$customer_id=$data['entity_id'];

How to get Category Id of current product in magento

$categoryIds = $_product->getCategoryIds();      
            if(count($categoryIds) ){
                $firstCategoryId = $categoryIds[0];
                $_category = Mage::getModel('catalog/category')->load($firstCategoryId);

                echo $_category->getName();
               echo $_category->getId();
            }

Magento Select Query

$connectionWrite = Mage::getSingleton('core/resource')->getConnection('core_read');
$resource = Mage::getSingleton('core/resource');
$tableName = $resource->getTableName('marketplace_product');
$query = 'SELECT userid FROM ' . $tableName . ' WHERE mageproductid = '.(int)$product_Id ;

$userid = $connectionWrite->fetchOne($query);