I have just switched over to using Xcode 5.
I have gone to change the name of my application with some other settings which I need to change, However when I have gone to do thi
See up in the left hand corner of your screenshot the blue icon? You have your project file selected and are viewing the project's global settings, which don't have a "General" tab.
Click either the triangle in the box up there or the lower blue icon with "template" and select a build target.