How do I get out of 3D view I was working on an intro and then I managed to click a random button and now, all the tabs on the side were replaced by something that looked like this:


I really need to fix this so I can get back on track. So can you guys help me since I'm just new to this Software.
You just switched the editor (window) type. 

All you have to do is click on the Window type button (first button in the header), and switch the window back to Properties.