Так как я фронтенд разработчик а это решение реализуется из бекенда, я все таки нашел решение как вывести все товары из всех категорий на главной странице сайта на opencart.

Для этого нам нужно будет изменить файл \catalog\controller\common\home.php и полностью изменить код в нем на тот что ниже. После этого у вас на главной странице будут выводится  все товары c вашего сайта на опенкарт

<?php
  
  class ControllerCommonHome extends Controller {
    public function index() {
      
      
      if ((isset($_SERVER['HTTPS']) && (($_SERVER['HTTPS'] == 'on') || ($_SERVER['HTTPS'] == '1'))) || $_SERVER['SERVER_PORT'] == 443) {
        define('HTTP',"https://");
        } elseif (!empty($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https' || !empty($_SERVER['HTTP_X_FORWARDED_SSL']) && $_SERVER['HTTP_X_FORWARDED_SSL'] == 'on') {
        define('HTTP',"https://");
        } else {
        define('HTTP',"http://");
      }	
      
      define('HOST', HTTP.$_SERVER['HTTP_HOST']);	
      
      
      
      $this->document->setTitle($this->config->get('config_meta_title'));
      $this->document->setDescription($this->config->get('config_meta_description'));
      $this->document->setKeywords($this->config->get('config_meta_keyword'));
      
      
      
      $this->load->language('product/category');
      
      $this->load->model('catalog/category');
      
      $this->load->model('catalog/product');
      
      $this->load->model('tool/image');
      
      if (isset($this->request->get['filter'])) {
        $filter = $this->request->get['filter'];
        } else {
        $filter = '';
      }
      
      if (isset($this->request->get['sort'])) {
        $sort = $this->request->get['sort'];
        } else {
        $sort = 'p.sort_order';
      }
      
      if (isset($this->request->get['order'])) {
        $order = $this->request->get['order'];
        } else {
        $order = 'ASC';
      }
      
      if (isset($this->request->get['page'])) {
        $page = $this->request->get['page'];
        } else {
        $page = 1;
      }
      
      if (isset($this->request->get['limit'])) {
        $limit = (int)$this->request->get['limit'];
        } else {
        $limit = $this->config->get('theme_' . $this->config->get('config_theme') . '_product_limit');
      }
      
      
      $data['compare'] = $this->url->link('product/compare');
      
      
      function str_replace_once($search, $replace, $text) 
      { 
        $pos = strpos($text, $search); 
        return $pos!==false ? substr_replace($text, $replace, $pos, strlen($search)) : $text; 
      }			
      

      $data['products'] = array();
      
      $filter_data = array(
      'filter_category_id' => 0,
      'filter_filter'      => $filter,
      'sort'               => $sort,
      'order'              => $order,
      'start'              => ($page - 1) * $limit,
      'limit'              => $limit
      );
      
      $product_total = $this->model_catalog_product->getTotalProducts($filter_data);
      
      $results = $this->model_catalog_product->getProducts($filter_data);
      
      foreach ($results as $result) {
        if ($result['image']) {
          $image = $this->model_tool_image->resize($result['image'], $this->config->get('theme_' . $this->config->get('config_theme') . '_image_product_width'), $this->config->get('theme_' . $this->config->get('config_theme') . '_image_product_height'));
          } else {
          $image = $this->model_tool_image->resize('placeholder.png', $this->config->get('theme_' . $this->config->get('config_theme') . '_image_product_width'), $this->config->get('theme_' . $this->config->get('config_theme') . '_image_product_height'));
        }
        
        if ($this->customer->isLogged() || !$this->config->get('config_customer_price')) {
          $price = $this->currency->format($this->tax->calculate($result['price'], $result['tax_class_id'], $this->config->get('config_tax')), $this->session->data['currency']);
          } else {
          $price = false;
        }
        
        if ((float)$result['special']) {
          $special = $this->currency->format($this->tax->calculate($result['special'], $result['tax_class_id'], $this->config->get('config_tax')), $this->session->data['currency']);
          } else {
          $special = false;
        }
        
        if ($this->config->get('config_tax')) {
          $tax = $this->currency->format((float)$result['special'] ? $result['special'] : $result['price'], $this->session->data['currency']);
          } else {
          $tax = false;
        }
        
        if ($this->config->get('config_review_status')) {
          $rating = (int)$result['rating'];
          } else {
          $rating = false;
        }
        
        $data['products'][] = array(
        'product_id'  => $result['product_id'],
        'thumb'       => $image,
        'name'        => $result['name'],
        'description' => utf8_substr(trim(strip_tags(html_entity_decode($result['description'], ENT_QUOTES, 'UTF-8'))), 0, $this->config->get('theme_' . $this->config->get('config_theme') . '_product_description_length')) . '..',
        'price'       => $price,
        'special'     => $special,
        'tax'         => $tax,
        'minimum'     => $result['minimum'] > 0 ? $result['minimum'] : 1,
        'rating'      => $result['rating'],
        'href'        =>   $this->url->link('product/product', 'path=' . null . '&product_id=' . $result['product_id'] )
        );
      }
      
      
      
      $url = '';
      
      if (isset($this->request->get['filter'])) {
        $url .= '&filter=' . $this->request->get['filter'];
      }
      
      if (isset($this->request->get['limit'])) {
        $url .= '&limit=' . $this->request->get['limit'];
      }
      
      
      $data['sorts'] = array();
      
      $data['sorts'][] = array(
      'text'  => $this->language->get('text_default'),
      'value' => 'p.sort_order-ASC',
      'href'  => HOST . ('/?sort=p.sort_order&order=ASC' . $url)
      );
      
      $data['sorts'][] = array(
      'text'  => $this->language->get('text_name_asc'),
      'value' => 'pd.name-ASC',
      'href'  => HOST . ('/?sort=pd.name&order=ASC' . $url)
      );
      
      $data['sorts'][] = array(
      'text'  => $this->language->get('text_name_desc'),
      'value' => 'pd.name-DESC',
      'href'  => HOST . ('/?sort=pd.name&order=DESC' . $url)
      );
      
      $data['sorts'][] = array(
      'text'  => $this->language->get('text_price_asc'),
      'value' => 'p.price-ASC',
      'href'  =>HOST . ('/?sort=p.price&order=ASC' . $url)
      );
      
      $data['sorts'][] = array(
      'text'  => $this->language->get('text_price_desc'),
      'value' => 'p.price-DESC',
      'href'  => HOST . ('/?sort=p.price&order=DESC' . $url)
      );
      
      if ($this->config->get('config_review_status')) {
        $data['sorts'][] = array(
        'text'  => $this->language->get('text_rating_desc'),
        'value' => 'rating-DESC',
        'href'  => HOST . ('/?sort=rating&order=DESC' . $url)
        );
        
        $data['sorts'][] = array(
        'text'  => $this->language->get('text_rating_asc'),
        'value' => 'rating-ASC',
        'href'  => HOST . ('/?sort=rating&order=ASC' . $url)
        );
      }
      
      $data['sorts'][] = array(
      'text'  => $this->language->get('text_model_asc'),
      'value' => 'p.model-ASC',
      'href'  => HOST . ('/?sort=p.model&order=ASC' . $url)
      );
      
      $data['sorts'][] = array(
      'text'  => $this->language->get('text_model_desc'),
      'value' => 'p.model-DESC',
      'href'  => HOST .('/?sort=p.model&order=DESC' . $url)
      );
      
      

      
      $data['limits'] = array();
      
      $limits = array_unique(array($this->config->get('theme_' . $this->config->get('config_theme') . '_product_limit'), 25, 50, 75, 100));
      
      sort($limits);
      
      
      $url = '';
      
      if (isset($this->request->get['filter'])) {
        $url .= '&filter=' . $this->request->get['filter'];
      }
      
      if (isset($this->request->get['sort'])) {
        $url .= '&sort=' . $this->request->get['sort'];
      }
      
      if (isset($this->request->get['order'])) {
        $url .= '&order=' . $this->request->get['order'];
      }
      
      
      
      foreach($limits as $value) {
        $data['limits'][] = array(
        'text'  => $value,
        'value' => $value,
        'href'  => HOST . str_replace_once('&', '?', $url. '&limit=' . $value)
        );
      }
      

      $url = '';
      
      if (isset($this->request->get['filter'])) {
        $url .= '&filter=' . $this->request->get['filter'];
      }
      
      if (isset($this->request->get['sort'])) {
        $url .= '&sort=' . $this->request->get['sort'];
      }
      
      if (isset($this->request->get['order'])) {
        $url .= '&order=' . $this->request->get['order'];
      }
      
      if (isset($this->request->get['limit'])) {
        $url .= '&limit=' . $this->request->get['limit'];
      }
      
      $url = str_replace_once('&', '?', $url);			
      

      $pagination = new Pagination();
      $pagination->total = $product_total;
      $pagination->page = $page;
      $pagination->limit = $limit;
      $pagination->url = HOST . ($url . '/?page={page}');
      
      $data['pagination'] = $pagination->render();
      
      $data['results'] = sprintf($this->language->get('text_pagination'), ($product_total) ? (($page - 1) * $limit) + 1 : 0, ((($page - 1) * $limit) > ($product_total - $limit)) ? $product_total : ((($page - 1) * $limit) + $limit), $product_total, ceil($product_total / $limit));
      

      if ($page == 1) {
          $this->document->addLink(HOST, 'canonical');
        } else {
        $this->document->addLink(HOST . ('/?page='. $page), 'canonical');
      }
      
      if ($page > 1) {
          $this->document->addLink(HOST . ((($page - 2) ? '/?page='. ($page - 1) : '')), 'prev');
      }
      
      if ($limit && ceil($product_total / $limit) > $page) {
          $this->document->addLink(HOST . ('/?page='. ($page + 1)), 'next');
      }
      
      $data['sort'] = $sort;
      $data['order'] = $order;
      $data['limit'] = $limit;
      
      $data['continue'] = $this->url->link('common/home');
      
      $data['column_left'] = $this->load->controller('common/column_left');
      $data['column_right'] = $this->load->controller('common/column_right');
      $data['content_top'] = $this->load->controller('common/content_top');
      $data['content_bottom'] = $this->load->controller('common/content_bottom');
      $data['footer'] = $this->load->controller('common/footer');
      $data['header'] = $this->load->controller('common/header');
      
      $this->response->setOutput($this->load->view('product/category', $data));
      
    }
  }

Если вам была полезна данная статья, то поделитесь данной статьей в социальной сети. А если вам нужна помощь в настройке сайта, нужна верстка или что то еще то жду Вас на kwork .