Three key points to bear in mind
1 - A tourist visa cannot be converted into a student visa in France or in any other country of the European Union.
2 - If you plan to attend two programs in succession (such as program In French as a foreign language followed by an academic program), obtain admission to both programs before applying for your visa so that your visa will be valid for your entire period of study.
3 - International students (other than European Union nationals) residing in France for more than three months must register at the local branch of the OFII (French Office for Immigration and Integration) in the three months following the arrival in France. For this registration, student must provide the special OFII form issued to the student at the time of visa issuance in Hong Kong.