Its normal for cats to scratch. It is instinctive and and inherited trait.
Cats scratch in order to leave a visual and olfactory smell that marks their territory.
There are sweat glands in their paws that leave the scent. They will also scratch in order to condition and trim their claws and to provide muscle toning in the front legs. Close off all areas tha might be a problem and keep your cat confined to an area that does not have any objects that might be scratched. Provide an alternate scratching post or board of a sufficient size and texture to encourage the cat to use it, yet sturdy enough so as not to tip over. It should be covered with a material with a longitudinal weave that allow syour cat to dig its claws in and get a long stroke.