How to turn off Opera Mini "discover"/"top stories" news feed?
There is an option under Settings, but it's tucked away under Advanced settings and the wording might not be intuitive to people unfamiliar with browser jargon:


In the popup settings menu from the Opera icon in the bottom right, (or menu button if you have one), choose Settings > Advanced > Start page content
Switch from Default to Speed Dial only


This turns off the news feed on the new tab home page.