Can I get DOF with kit lens (18-55mm) using a Nikon D3100?

I wold like to get this camera, but i'm beginner, can i get this effect?

First you have to know what depth of field is.

ALL lenses create depth of field. How much depends upon the focal length of the lens and the aperture you use.

You can demonstrate this to yourself by shooting with your lens wide open at 18 mm and wide open at 55 mm with the subject close to your lens (maybe 4 feet). Do the same but with the aperture set to f/16 and then look at the differences in the depth of field

Of course you can. If you couldn't then no photo taken with that camera and lens could be in focus.

I think you better do some research into what depth of field is…

Yes you can. The DOF looks really good. What also is important though, is that you can't zoom too far with 18-55 mm = it's more for portrait or close up photos. If you want to be further away and still get DOF you can consider the 55-200/300 mm lens.

But yes you can get this effect really well. That camera is the best choice!