I finished this Camino last month, starting from Malaga Airport, on a mountain bike. Up until Cordoba I came across a total of 3pilgrims (1 in the opposite direction). From Cordoba to Merida no more than 2/day and after Merida a maximum of 6/day, dropping back down to 3 or 4 a day from Granji and the odd one more after Ourense. However, about 15miles before SdC I passed around 200! As for accommodation, there are resources on the web if you search, as is the route and guide, all free, in addition to the well known apps for VdP and Sanabres which are only about £2 for the premium versions. You may be the only one in the alburgue, so well worth ringing ahead to make sure it's open. You can also book rooms on Booking.com. Generally it's a well sign posted route, but you are strongly advised to have the apps on your phone with offline maps or plot them yourself b4 you start on Komoot or similar. Buen Camino