Iam coming China first time to visit Beijing

If I undestand it correctly, your destinations is near local Sunhe MTR Station along subway line 15. Well, from the airport, you can take Express Train to Dongzhimen, where transfer to subway line 13 to Wangjng West. At this station, transfer to line 15 to get off at Sunhe Station and then walk to your destination.

Sunhe is very nearer to BJ Airport. The easiest way is to take a taxi (It will not cost more than 40-50 RMB). I would not advice to a new commer to take subway line 15, because after getting off from line 15 its alomst more than 2 kilometer's walk, and you can not travell along with luggage this distance, again you have to take some tranport from Sunhe subway station. So it better to take a direct transpot from airport to Sunhe. All the best