I want to enjoy the local sites on the public transport.To visit the Great Wall of China

The nearest tourist spot is Chaoyang Park, which is about 2 mi (3.3 kilometers) southeast from your hotel.
To visit the local sites, both bus and taxi are ok. Besides, some sites can be reached by subway.

To the Great Wall, if you want to go to Badaling, the suggested transportation is like this: walk northwards to Sanyuan’an, take bus Yuntong 104 there to Xizhimen Outer. And then walk northwards to the North Railway Station. There you can take S trains to reach Badaling.