Depending on your nationality, your situation and the length of your stay, you might need a visa to pursue your studies in France.
If you are an Irish citizen, you do not need any Visa!
For non-European citizens
If you are non-European, you will need a Visa to do your studies in France.
There is an official website for visa application to France : https://france-visas.gouv.fr/
You will find all information you need to prepare your stay in France.
In order to apply, you need to directly contact the French Consulate in Ireland.
More information about the application and your appointment here: https://ie.ambafrance.org/Student-Visa