Can you use subway from king park view hotel to get to the Great Wall or close? Which lines?

There is no subways can take you to the Great Wall directly.
It is suggested to take a taxi to Deshengmen West from your hotel. From Deshengmen West, you can easily find bus 919 taking you to reach the Great Wall directly. From your hotel to Deshengmen West, the distance is around 5km.