Magento 2 – Get Shipping and Billing Address of Customer After Order Placed

$templateVars = array(
        'store' => $this->storeManager->getStore(),
        'message'   => 'We processed your order ID We will contact you soon in mail for the acknowledgement if you not receive mail within 4 hours please get help from support@xxx.com',
        'order' => $order,
        'store'=> $store,
        'productName'=> $productName,
        'payment_html' => $this->getPaymentHtml($order),
        'formattedShippingAddress' => $this->getFormattedShippingAddress($order),
        'formattedBillingAddress' => $this->getFormattedBillingAddress($order),
   );

Try this below function, pass shipping Address Data object as a param to the getShippingDetail() function from mainfunction() and it will return the customer first and last name as array

public function mainfunction($orderObj)
{
    $_ShippingObject = $orderObj->getShippingAddress();
    $_customer_data = $this->getShippingDetail($_ShippingObject);
    echo "<pre>";print_r( $_customer_data );
    exit;

}


public function getShippingDetail($_ShippingObject)
{

    $shippingArray['First_Name'] = $_ShippingObject->getData('firstname');
    $shippingArray['Last_Name'] = $_ShippingObject->getData('lastname');
    return $shippingArray;

}