With this type of camera, you just buy the lens you want. You must use a lens that is compatible, all Canon autofocus lenses will work fine.


You choose the focal length of the lens according to the view you want, wide angle for landscape, normal for a natural lookiing image, or telephoto for more distant things.


The 18-55mm kit zoom lens is a starter that covers wide ot slightly telephoto and is good to help you devide just which focal lengths work for you. Its cheap, but takes excellent images.


I really do not recommend spending $1000 for a lens like the 17-55mm f/2.8 until you know it will work for you. If your sister has some lenses you can try, that might help you decide.


The problem with asking others for advice is that everyone has a different opinion according to what they like, and it may not be even close to what you like.


Thats why the kit lens is a good idea for starters.