I want to buy sport shoes. Which area or shopping center will you recommend in Nanjing? Can I go by subway.

There are many sport items near local Wutaishan Stadium, so you may go there to have a look.
You can take the subway line 1 to reach Zhujiang Road Station. Get out of the station from Exit 1 and walk along Guangzhou Road, you can reach the stadium directly.

Or you can use the subway line 1 to reach Xinjiekou Station. Get out of the station, you can find many big shopping malls, inside, you can find many sport shoes in different brands.