You can find tons of free French records online without having to create any account. Birth, marriage, death, census, military, war, notary records, to name a few. All of these records are organized by department (département), and each département has its own website, with its own digitized archives (archives numérisées). So in order to start your research, you will need to know what département your ancestor was located in. For this, visit the “Regions and Departments of France” section.