Hi Annali,
I am not long back from having walked from Valenca to Santiago. I too am in my mid 70's and having walked from the Pyrenees to Santiago 3 times with rucksack on my back and not knowing where I would stay I decided this year to book ahead and send my rucksack by Tuitrans.
Not having to carry my ruck made a huge difference to my enjoyment of the Camino. However it did mean that I had to book ahead most of the time. Although Tuitrans will deliver the ruck to somewhere near by when necessary (e.g. Hebron). I used the website caminodesantiago.consumer.es. This site gives reviews of albergues and meant that I could avoid the odd one. I also used www. booking.com. Some private albergues cost €10 only, whilst this a little more than a Xunta albergues it is well worth it to be sure of a bed. Tuitrans cost €5 a day.
I have already booked my flights and am half way through booking accommodation for a Spring Camino
Buen Camino to you both
Lydia
P.S. There is a very steep downhill with boulders just South of Valenca