So let's say you want to remove the title block from the success page.
First you will need to find the xml that is responsible for that specific page in our case it will be vendor/magento/module-checkout/view/frontend/layout/checkout_onepage_success.xml
And in this file you will have the following content:
<?xml version="1.0"?>
<!--
/**
* Copyright © Magento, Inc. All rights reserved.
* See COPYING.txt for license details.
*/
-->
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" layout="1column" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<head>
<title>Success Page</title>
</head>
<body>
<referenceBlock name="page.main.title">
<block class="Magento\Checkout\Block\Onepage\Success" name="checkout.success.print.button" template="Magento_Checkout::button.phtml"/>
<action method="setPageTitle">
<argument translate="true" name="title" xsi:type="string">Thank you for your purchase!</argument>
</action>
</referenceBlock>
<referenceContainer name="content">
<block class="Magento\Checkout\Block\Onepage\Success" name="checkout.success" template="Magento_Checkout::success.phtml" cacheable="false">
<container name="order.success.additional.info" label="Order Success Additional Info"/>
</block>
<block class="Magento\Checkout\Block\Registration" name="checkout.registration" template="Magento_Checkout::registration.phtml" cacheable="false"/>
</referenceContainer>
</body>
</page>
You will now need to extend this xml in your theme app/design/frontend/.../.../Magento_Checkout/layout/checkout_onepage_success.xml
And inside it reference the block you need to remove page.main.title
and add remove="true"
like so:
<?xml version="1.0"?>
<!--
/**
* Copyright © Magento, Inc. All rights reserved.
* See COPYING.txt for license details.
*/
-->
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" layout="1column" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<head>
</head>
<body>
<referenceBlock name="page.main.title" remove="true" />
</body>
</page>
If you wish to remove a specific block from all cms pages you can achieve this by extending the default xml vendor/magento/module-theme/view/frontend/layout/default.xml
in you theme folder app/design/frontend/.../.../Magento_Theme/layout/default.xml
like so:
<?xml version="1.0"?>
<!--
/**
* Copyright © Magento, Inc. All rights reserved.
* See COPYING.txt for license details.
*/
-->
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<body>
<referenceBlock name="page.main.title" remove="true" />
</body>
</page>