//di.xml file
<?xml version="1.0" encoding="utf-8"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="Magento\Quote\Model\Quote">
        <plugin name="limit_cart_items_plugin_name" type="YourVendor\YourModule\Plugin\Quote\ClassName" sortOrder="10" disabled="false"/>
    </type>
</config>
//YourVendor\YourModule\Plugin\Quote
<?php
namespace YourVendor\YourModule\Plugin\Quote;
use Magento\Quote\Model\Quote;
use Magento\Framework\Exception\LocalizedException;
class ClassName
{
    public function beforeBeforeSave(Quote $subject)
    {
        $customerGroupId = $subject->getCustomerGroupId();
        // Define the customer group(s) you want to restrict
        $restrictedCustomerGroups = [1, 3];
        // Check if the customer group is in the restricted list
        if (in_array($customerGroupId, $restrictedCustomerGroups)) {
            // Get the items in the cart
            $items = $subject->getAllItems();
            // Define the maximum number of items allowed in the cart
            $maxItemsAllowed = 2;
            // Define the maximum cart total amount and here get specific amount
            $maxCartTotal = 120; 
            $totalQty = 0;
            $cartTotal = 0;
            $itemsToRemove = [];
            foreach ($items as $item) {
                $totalQty += $item->getQty();
                $cartTotal += $item->getRowTotal();
                // Check if the item quantity exceeds the limit
                if ($item->getQty() > $maxItemsAllowed) {
                    $itemsToRemove[] = $item;
                }
            }
            // Check if the cart exceeds the limits
            if ($totalQty > $maxItemsAllowed || $cartTotal > $maxCartTotal) {
                // Remove extra items
                foreach ($itemsToRemove as $itemToRemove) {
                    $subject->removeItem($itemToRemove->getId());
                }
                throw new LocalizedException(__('You can only add up to 2 products to your cart. and maximum amount 120.'));
            }
        }
        return [$subject]; 
    }
}