When you go on probation, you are usually asked to type documents, organize files and run errands. Generally, you are not allowed to write specific practical documents, because judges and prosecutors are responsible for any mistakes.
During the probation period, no one will teach you specifically. Generally, you are placed in a department, arranged by a judge or prosecutor, or you are a mobile person in the department, which will let you help everyone who needs you.
You'd better be an intern at the court. The court is too busy. As long as you are a regular law student, they will accept you. As for the procuratorate, it is too professional and politically serious, and it is not suitable for probation. The words of the Bureau of Justice are mainly about judicial assistance and judicial examination registration. And their professionalism is not strong.