There are all kinds of "blurry"; some are supposed to be there and some are not. DSLRs are great for the blur that is supposed to be there, called depth of field (DOF). It is directly related to the aperture setting used for a photo. The aperture also controls how much light is allowed into the lens.
Say you set your kit lens at 24mm. The camera can use an aperture number from f4 to f27. The lower an f number is, the wider the lens is open and the more light is allowed in. That's good, but also remember that with lower f numbers, less of the photo in front and in back of the subject will be in perfect sharp focus. That can be an effect that makes a great photo, or an annoying problem.
Here's an example of very small depth of field. I think this was f2. You can see the tip of the nose is blurry, sharpness increases closer to the eye, then the back of the head is blurry. That's because of a very narrow DOF. Probably f5.6 would have gotten the rest of the head in sharp focus.
Distance also is a factor in depth of field. When you're really close, the in-focus area may be only inches at f4. At a mile away, it might extend to the horizon.
If you post an example photo, the first thing I'd look at is your aperture setting, to see if you had enough depth of field. Another kind of blur is motion blur, where the camera or subject is moving while the shutter is open. A third kind is a focusing problem, where the camera or you did not focus on the intended sublject.
Rule out those and we get to lens problems. No lens is perfect, and the degree of perfection is somewhat related to price. The kit lens is a lot better than its price would suggest but does have issues. I have never noticed unexpected blurriness, that's why I have this last. If your lens is working correctly, its flaws are only obvious at its extremes: 18mm or 55mm and small f numbers. Backing off from those settings can help a lot, say 21mm instead of 18mm.