Make the scratching post more inviting by setting cat toys next to it. When you do this the cat will be more accepting to the post. Attract your cat to scratch by tossing some tasty treats around the post, setting up cat toys around the base of the post and spraying the entire scratching area with liquid catnip. Be generous with the catnip training product.
Watch your cat for inappropriate scratching. If your cat goes to file their nails on the carpet or your favorite wicker chair then pick up your cat and bring them back to their scratching post.
I do not recommend declawing a cat as it is very painful and can cause the cat to have improper balance and behavior problems including biting.
One of my rescued cats was declawed. She was left in the woods by my home. She could not climb a tree for safety, fend off predators or hunt for food. As a result of the declawing she cannot jump on the sofa.