HI Dave,
Best wishes on your upcoming Camino. I hope you post here on the Way to share the sights of autumn with all of us!
Your credencial will be no problem. Most of the albergues can sell you one. I filled my first one and needed to buy a second in Hospital de Orbigo, but I saw people who had lost theirs get a replacement in a variety of albergues. Some poeple opted to get second stamps in their journals and others got stamps in their journals from places like churches, cafés, bars, etc. just so they had the stamp but didnt' want to fill more than one credencial with the sellos. So there are lots of possibilities - keep your eyes open and you will see lots of variety!
Do be aware however, that you need the credencial in order to stay at an albergue and for some (who give preference to Pilgrims "a pie" on foot) they will look at the previous nights stamp in order to see how far you've walked in a day.
I highly recommend taking a small (or a few small) zip lock bags in order to keep you passport(s) dry. It was a trick I learned on the Way (too late for me) and wished I had thought to do it. Keeps everything dry from sweat, spills, moisture and rain.
Buen Camino, :arrow: