live near Tucheng Station Wanna go to Haichang polar marine park in Tianjin. How long will it take by subway.

From the station to the park, there is no direct subway train can take you to reach from that station.
I suggest you to take a taxi to reach Dongxinglu Station of the local Light Rail to take that light rail to reach Tanggu Station. Then you can take a taxi to reach that park.