To remove the title of a particular page all you need to do is edit the page and locate the “Template” down the right hand side. Then just select the appropriate template you wish to use ensuring that it’s the “No Page Title” version. So for example if you would like to use the Full With template you should select, “Full Width, No Page Title”.
Alternatively if you would like to remove all titles from all pages on the whole site then just navigate to Appearance > Customize > Layout. There you will see two options – “Display Page Titles” and “Display Post Titles”. These will allow you to toggle the displaying of all page title and all post titles respectively.