How much will it cost to repair the damage to the wallpaper in the studio apartment?

Hello, I have just rented my first studio apartment in Korea. However, while trying to remove a hook that was hanging on the wall, the wallpaper got slightly torn. I'm worried about how much it will cost to repair this. Also, I want to decorate the room by hanging mirrors or pictures on the wall, but I'm concerned that it might damage the wallpaper. If the wallpaper gets damaged, I'm a bit anxious that the landlord might charge me for the repair costs from my deposit. The landlord is very kind, but I'm unsure how to bring up this issue. If anyone has had a similar experience, could you please share how much the wallpaper repair cost was, or how to communicate effectively with the landlord? Thank you.