Nikon D3200 settings problems?

I just got my first DSLR, it's a Nikon D3200 and I'm extremely happy with it, but I'm having issues with ISO, aperture and focus settings. Before, I could change the ISO all the time by holding in the "Fn" button the side and scroll on the wheel to the right, but now that doesn't work. Aperture I haven't figured out how to use, it says that I should click the +- button on the top right and scroll the wheel, but nothing happens. The third problem I have is my focus settings, yesterday I could just switch between auto and manual by clicking the info button, but the option for focus is greyed out.

What am I doing wrong here?

P.S. Keep in mind that this is my first DSLR like I said so I'm more or less clueless when it comes to these types of technical aspects of photography.

If you can't find all your answers in the Owner's Manual you should seriously consider getting a Nikon D3200 For Dummies. The Dummies book can get you an answer to any question in only a few minutes. Check this out:
http://www.amazon.com/...1118446836

Have you bothered to read your owner's manual? All your answers are there.

You need to read your manual back to back
Also try the digitutor, http://www.nikondigitutor.com/eng/d3200/

Put your camera down and pick up the Owner's Manual. Now read and study the Owner's Manual.

Watch this video tutorial:
http://www.nikondigitutor.com/eng/d3200/index.html Who better than Nikon to teach you how to use your Nikon D3200?

These sites will also help you:

http://digital-photography-school.com/learning-exposure-in-digital-photography

http://www.photographymad.com/pages/view/10-top-photography-composition-rules

http://photographyknowhow.com/quality-of-light-in-photography/
http://photographyknowhow.com/direction-of-light-in-photography/

The autofucos on my D3200 does not work