No training. You can sign up for the exam directly. The training is mainly aimed at people with strong accents and people who attach great importance to exams but don't understand them. There are training materials, which will contain the contents of the question bank. If you are worried about the exam, you can buy textbooks to practice. If you think your Mandarin is still standard, there is no need to take any training. If you are good at oral expression, you don't even have to prepare yourself.