In addition to what Camino Chrissy wrote in the above post be sure to check out the other entries in the forum section Other Routes in France.
Check
this recent thread re walking from Paris to Santiago.
From a Belgian site check out this
page and aim for Massy the first day. Massy is 18 km. from Notre Dame cathedral in Paris. The Belgian site offers invaluable info re walking/stopping from Paris south. Do explore the other links on that site.
THIS is also useful for walking to Massy.
Here is a
thread from a pilgrim who walked from Paris in 2022.
Do be aware of the donativo
Chaîne d'Hospitalité Locale.Those who offer pilgrims such hospitality do so for the pleasure of meeting/greeting/helping pilgrims.
During past easier years my husband and I ran a b&b/pilgrim house in our farmhouse facing the Marne river as part of the local Chaine. My first pilgrim shell hung at the door marking it as a pilgrim place.
However/wherever you do walk,
Bon chemin!