I walked Paris/Saint-Jean d-Angeles this past August, September. I’m an 84 YO woman traveling alone and can only go about 12 miles max each day. It was a challenge finding places at such short intervals, yet somehow I did it. MMDD is a huge help. And the advice from Threewishes above about the associations is excellent. (At one point, I was “passed along” from one place to another via the friendships of the hostelliers. THAT was really great.). Be mindful that Mairies are usually not open weekends, Mondays, and holidays. Also, many in the smaller villages are open only half days—some in the mournings and some in the afternoons.
Knowing how to really use your cell phone is helpful and a good smattering of French is very convenient for understanding.