Using only alias URL for a page If I've got a page that originally has a node (ie node/20) for the URL and then if I've assigned its own custom URL (ie website.com/landingpage) I'm finding that I can still access the page by using its node number. 
Ideally I'd like to have it so a user can only access the page via the custom URL and never the node so is there a way I can configure a node so it cant be used in the URL to reach the page?
You can use the Redirect module for this: https://www.drupal.org/project/redirect