You can change the word "checkout" in the URL to something else. Add a etc/frontend/routers.xml file to any of your modules with the following content:
<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:App/etc/routes.xsd">
<router id="standard">
<route id="checkout" frontName="thenameyouwant">
<module name="Magento_Checkout" />
</route>
</router>
</config>
Take care that your module is being loaded after the Magento_Checkout module, i.e. by modifying your etc/module.xml as follows:
<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
<module name="Your_Module" setup_version="0.1.0">
<sequence>
<module name="Magento_Checkout"/>
</sequence>
</module>
</config>
You cannot change the whole path easily, that'd be much more complicated.
Andreas von Studnitz, Trainer, Consultant, Developer and CEO of integer_net, Germany.