Because you can't prioritize Pages you don't follow, you should also add some new sources. While you're on the same settings page, scroll down and click Discover Pages that match your interests. This brings up a list of public Pages, not personal profiles, with which you might want to connect. If you see anything of interest, click the relevant Like button, and Facebook will integrate that source into your News Feed. You can also seek out specific news outlets by typing their names into the search box at the top of the page. Click through to that outlet's Page, select Follow, then choose See first to promote it in your News Feed.