I recommend starting in Saint Jean Pied du Port on the French side of the Pyrenees.
The first days walk is one of the toughest because the Camino takes you over the mountains to Roncesvalles, about 27 kms from SJPP.
Saint Jean Pied du Port to Santiago is 780 kms, more or less.
It takes 31 days at 25 km per day.
Scroll down through this forum and you will find out all about how to get to SJPP and the walk to Roncesvalles.
Buen Camino,
David, Victoria, Canada.