After a database upgrade of a 2007 site to 2013 (with the obligatory pitstop in 2010), the page titles of sites don't appear. On sites created in 2013, the title appears at the top of the Home page and it is clickable. Nothing appears on an upgraded site and there doesn't seem to be a way to edit the page to get it there like you can on 2007 pages.
You notice that sites that were created in 2013 have a sitepages library, but you can't find a template to create that app on your migrated sites.
The new home page in 2013 is not exactly a web part page - instead it is has rich content areas. It has more in common with a Wiki page than the old style Web part pages. You can still create the Web part pages of yore, but it is hidden in the Site pages library. There is no way to manually create the sitepages library, but that is as designed.
Make a new page after the site is upgraded. They system creates the sitepages library for you in the process.
Site Actions -> Add a page. When you click on this for the first time, there is a pop-up:
I named the page default, then clicked on Create. For a short time, the title on the page will be default, but it will change later.
From here you can do two things. One is change the page layout:
When you click on that, it will give you warning that you cannot navigate to the original page once you change it. Click on OK. The title of the page will now be updated to what is in the Site Settings.