Help! No I have no idea how to change the aperture

I got the Nikon 1 as a gift and really have no idea how to use it.... All I've ever had was a point and shoot. When playing around with the settings I'm assuming I changed the aperture and some other things.  I was able to get really focused one the subject only and not the background (it was blurry)... But now I have no idea how I did that if  anyone could give any tips to this very new camera owner it would be really appreciated