The official text of any treaty to which France is a signatory is that published in the Journal Officiel. (JO from 1990 available via Legifrance.)
The Ministère des Affaires étrangères hosts a free online database Base Pacte This will provide at least the following: title, date of signature and publication details. A selection of treaties are available in full-text. There are separate search screens for bilateral and multilateral treaties.
(It is also possible to search for those treaties to which France is not a signatory, but is the official depository.)
For an introduction in English see Chapter 8 of book below: