Hi i suggest that you put the camera in av mode this is where you set the aperture. Now set a low number f3.5 is your lowest with a kit 18-55 lens. Now do you want to take these pics in doors if so when then enter the realms of flash or no flash. I would try out doors first to eliminate the need for flash.
Im a bit confused on this advise as i too own the same camera
Im looking at the manual and it suggest f16. Ive tried both the settings and Im not getting a blurred background