You could reach Guangzhou first and then to Yiwu, last to Shijiazhuang and Tianjin. From Guangzhou to Yiwu, you could take flight or train. From Yiwu to Shijiazhuang, there are no direct trains, but you could transfer at Hangzhou. Many trains are running daily from Shijiazhuang to Tianjin. About the detailed train info., you can do a search on the website.