Can i sharpen my skates with a knife sharpener?

No. Skates blades have two short edges on a blade that's curved inward to make the edges, whilst knives taper to a sharp edge that can cut. Ice skating blades should not be able to do more than scratch you, unless something crazy happens. Trying to use a knife sharpener will pretty much dull it more. They need a special whetstone, and your rink should provide the service for less than $20.