Studying in a training school is a good way. If you take Grade 2, you need to finish Book 1 and Book 2 if you take Intermediate. Now the exam focuses more on listening and speaking ability.

Learning Japanese should be considered comprehensively. My friend, after the Japanese training class, come back and practice listening and speaking with cooking Japanese. She said that it is not enough to just attend classes, the key is to practice by yourself. There are special listening and speaking training methods for cooking Japanese. I have tried, and I can read difficult Japanese sentences fluently after reading them several times.