Nikon D3000 blurry when I look through it and won't take a picture?

I just bought this camera to start a photography course. I'm not sure how to use it yet so I just took a few pictures on Auto making sure it worked okay then put it in my camera bag. I took it out today to start my course and all of a sudden its really blurry when I look through it and it won't take a picture probably because it can't focus, I don't know. I was thinking about taking it somewhere but, since I just bought it I thought it may be something small and I wouldnt have to. Any suggestions would be great.

Added (1). My battery is fully charged

Added (2). I didn't touch ANY of the manual settings on the camera at all since I was going to learn all of this when I started my course. Like I said I just took a few photos and learned to put the lens on by reading the manual that came with the camera and put it away till this morning. Thats why I don't understand what's wrong…

Tara, is the battery fully charged?

Tell me this. Did you just get behind the wheel of a car and start driving? The same is true of cameras, of sophisticated cameras such as the D3000. You need to read the instruction book especially with today's electronic digital cameras. Everything is built into these cameras "perhaps EVEN the kitchen sink". I have been using cameras since I as 12 and film cameras are instinctively easy to operate. But today's digital's with their complex menu's must be practiced with, until one is familiar with the specific camera. The first thing I due with a new camera is read the instruction book even with my 45+ yrs of experience. Because the manufactures always seem to build in some "quirk" that I may not be aware of. Then I take the camera and read the book again! Not the most fun in the world, but a working knowledge of what you own will give you a lot more satisfaction!

Your lens will have a M/A-M switch. Make sure you did not inadvertently bump the switch into the M (manual focus) position. It should be in the M/A (Manual/Autofocus) position.

Here is a test you can try.

With the lens cap on, turn the camera on and depress the shutter half-way. The lens should cycle the focus from one end to the other, then back. This tells you that the focusing system is working.

If it doesn't, then again, make sure the M/A-M switch is correct, and that the lens is on properly. You might want to also remove the lens, then re-attach it.

Sometimes with new cameras, the electrical contacts don't always make contact until you have removed and reinstalled the lens a few times. So try that - as removing/installing the lens will have the effect of cleaning the electrical contacts.