Find a node/page in admin by looking at the code I'm very new to Drupal, and I want to edit some text on the front page. In the page.tpl.php, I have this code print render($page['content']), if I remove it, then the area that I want to edit with is disappeared from the front page, so I know this is the right part, but how can I find out which page, content, or node is being called in the backend?

I'm using Drupal 7.55.
I'd recommend installing the Devel module and enabling Webprofiler. It gives you a lot of useful meta information about the current request, including the controller and route used: