How to get rid of a duplicate title on the front page?
It sounds like you have node as your front page which lists summaries of content that is promoted to the front page by default. That's the way Drupal comes configured out of the box. If I understand correctly, what you're looking for though is a single node to be displayed in full on the front page.

You can change it from node (which shows a list) to your specific Node at admin/config/system/site-information or Configuration -> Site Information under the "Front Page" section. Simply change "node" to "node/[node-id]" where [node-id] = the nid of the node you want to appear on the front page: