Compared with Beijing and Shanghai, Hong Kong is closer to Qinzhou. But there is no direct train from Hong Kong to Qinzhou. You would better reach Guangzhou first and then take a train to Nanning. After that, you can take train or bus to Qinzhou, which is around 130kms from Nanning. And Qinzhou train station only has trains to Beihai, Nanning and Fangchenggang City.