I don't know if you already came to france or not.

As a french guy myself, I just can assure you that you won't regret your trip.
France is really a fantastic land to bike travel , and i don't exagerate.
This is why the "tour de france" is the most popular race in the road. Just look at it, and you have a beautiful and various scenery everyday
There is not musch dedicated bike path as in netherland or germany for example, but there are many well discribed path to follow, and a lot of secondary road.
To make it easy, just follow one of the well know river and you will find fantastic scenery everywhere. (loire, soane, rhone, .....).

Many website.
This one has some proposals

https://en.francevelotourisme.com/

This guy has also a nice youtube channel. This video is about the eurovelo 6 (vallée de la loire)
A lot of travel are in germany, but he also has some videos of travel to france. Just have a look to have an idea


Enjoy !