1. I suggest Dongao. I bought Dongao's book when I took the title test, and the title was very close. I passed the training class without applying.

2. If you don't have a professional background in accounting, you'd better sign up for a basic training class and take an accounting qualification certificate, because you need an accounting qualification certificate to apply for a junior professional title. Accounting qualification certificate takes three courses: accounting foundation, financial regulations and accounting computerization.

As for whether it will be useful in the future, it's really hard to say. It mainly depends on what occupation you are engaged in. Of course, accounting is useful. Besides, you are only a sophomore, so it's not a loss to learn more knowledge. With more knowledge, you will have a wider choice.