It is normal for a cat to climb and scratch, that is why it is important for them to have somewhere appropriate to climb.
Designate cat climbing objects or areas for your cat to use. For example, install a climbing post and connect it to a special viewing platform such as a bookshelf. You can even secure a box or small cat bed on the shelf so he/she can seek comfort from their viewing position.
If at first they are not interested in their new climbing equipment, place some of his/her favourite food treats or toys on the platform or shelf. Also make sure you use lots of positive encouragement when they are exploring the new area.