Welcome aboard and thanks for joining our family! This site is a good source for information in regards to our hobby of raising our very own flocks. Ask away and those in the know will chime in.
If you want to know what breeds you have, best look on a kind of Craigslist you have in France to see which breeds are common in your region.
Naked necks are quite common in France. Production reds too. But Australops and Delaware not so common in Europe. Big chance they are crossbreeds too. Which only makes them stronger.
If you post a few photos in the peeps in Europe thread, you might get a good answer too. Or tag a few people you find who know much about common breeds in Europe.
Unfortunately the online chicken encyclopaedia we have in the Netherlands is no longer safe to visit. It was a super website to dive into breeds with good descriptions and photos. Maybe there is a French one too?