Can someone help me understand Prime31?

I just can’t wrap my head around this stuff, and so I am in desperate need of some more knowledge about the Prime31 Gamecenter and Social Networking plugins. What I really need is to learn these plugins from the ground up, but I can’t teach myself and I can’t find anything out there to help me enough. Does anyone know of any video series or something like that, even people who can tutor me on this?

No, I am not aware of any tutorials or videos for this;)
Divide and conquer: try to get the simplest of the simple examples working, just to make sure the XCode plugin is installed correctly.

Gamecenter is a bit special since it relies on a lot of stuff being correctly configured on Apples end. It is not technically difficult, you just have to persevere.