1. After facing the problem of insufficient natural resources and following ambition to become a major global power, the Japanese Empire began aggressive expansion in 1930
2. Japan first expanded its empire to Manchuria, and Jehol which it invaded and conquered
I think Japan targeted this region because of seeking raw materials to fuel its growing industries.
3. In 1938 the Japanese launched several ambitious military campaigns that brought them deep into the heart of central China. They advanced to the northeast and west from Nanking, taking Suchow and occupying the Wu-han cities.
Sorry i don’t have time to answer all, hope this helps