Nikon D3100 won't focus anymore?

I got the camera yesterday. In my tinkering (testing different apertures an focus points mainly) I have somehow disabled focus of any kind-manual or auto. I don't know what I did because the lens doesn't focus in the view finder, it doesn't seem to do anything and all of my pictures are coming out 'fuzzy'. And this happens in every shooting mode, even in guide mode the lens will not focus. Does anyone know how I can correct this or why it won't focus?

*Lens is the standard one that comes with the entry level Nikon DSLRs: AF-S NIKKOR 18-55mm 1:3.5-5.6G

I'm a graphic design student and I've been using digital SLRs since I was 14, so I know a lot more about cameras than the average person. I'm still no expert but I have camera common sense.
I've read the manual from pages i-68 (the whole thing) and the CD that came with the camera. I've even googled it and I've noticed most of the answers are mean and very UNHELPFUL. So if anyone wants to be rude and tell me to "read the manual and stop thinking an expensive camera will make you a better photographer" please go play somewhere else. I have a real question and I think it would be awesome if I can get an answer or some legitimate recommendations that will help me improve on my craft.

Added (1). I've done everything. Like i said read the manual. I stepped back. I tried different lighting techniques. You know the sound the lens makes when it's focusing? The lens won't do any of that. It's just there. I can zoom, but that's it. No more.
I know how to focus it I've done it before, I did it yesterday and this morning. But like I said I went in and changed something and now it won't focus at all. And I would like to know if anyone knows what setting I might have touched to change it back. I've even done the "RESET SHOOTING OPTIONS" on the menu screen thinking that I would just start from scratch but it still won't focus.

Added (2). And yes, I know about the diopeter control next to the viewfinder. Tried that too and my images are still blurry.

Read the manual. Step back then try again. You may be just too near. If it's dark, try shooting under more light. If it still does not work, take off the lens then put it back on. If all else fails, return everything to the store. Do not forget to bring the sales receipt.

Yes, read the manual again after you open the new box. It all starts there.

You know everything… But you don't know anything… Sometime more brain can cause brain hoemerage.

You have *** up your lens motor. Get it repaired.

Two things which will cause this:
1. Switch on the side of the lens for manual and auto focus. Be sure it's on the auto position (might be marked M/A). Page 16 in your manual.

2.In the menus, you can set the camera to manual focus. Set this control to something other than MF, like AF-A. Pages 38 & 55 in your manual.