Easy, use Wikiloc web site , the site has millions of trailers done by hikers or pilgrims. Type the city name that you want to reach than make sure you had ckecked the case hike or walk not bike or car. Pick the one you want they might have more then one with different distance because they started from where they stayed the night before or the pilgrims walked more or less.
You could buy the application GPS Motion X $5 or $6 ( very easy to use they have a great customer service) download the track on your phone and follow the arrow like in your car plus you will save $$$ from books or maps. I have done that for each part of the camino prior leaving or for hiking in different country.
Good luck!