If you look at the front of your kit's zoom lens, you will see a mark with a number and a symbol ⌀. This is the diameter of the filter thread: to which front-end adapter lenses such as the ones you bought come together.
I think that in the 18-55 mm lens that comes with that camera, the value will be ⌀52. That will not work with the adapter lenses you bought. (I think some other Nikon 18-55mm lenses had a 55mm filter thread diameter, which may have resulted in confusing labeling of the things you bought).
You can buy what is called "52-55mm step up ring". The link goes to a generic one that I can not answer but should show you the general idea and the price ($ 7).
However, keep in mind that this type of front-mount adapter lenses are basically toys. They will introduce significant optical faults in the images taken. The telephoto adapter can actually be worst I just use the 55mm lens and cut it to simulate the zoom. Of course, you can not do that at the wide end, so the wide adapter can open up new possibilities, but it can not really replace a real wide-angle lens.
See Can bolt-on wide-angle adapters / converters produce decent quality results? for more on this.