French has no foundation, so you can apply for a beginner's class.
However, if you are a zero-based student, it is not recommended that you study, because the information content of the primary learning content is relatively small, and the tuition there is relatively expensive.
Shanghai French Union is a French school, so it pays more attention to listening and expression, and grammar teaching is not suitable for China students.
I recommend you to attend the training course of the School of Western Languages of Shanghai International Studies University. The tuition is very cheap, and the textbook is French, which is more suitable for laying a good foundation of grammar. My first teacher is Mr. Wu Xianliang, editor of Popular French. I think it is cost-effective. After reading two French books, it is also good to go to the French Union in Shanghai to strengthen oral English and listening.