Welcome George,
Walking with your son. What a great experience. I wish you well.
My youngest son walked Coast to Coast with me in the UK (West to East) and his elder brother and I walked Hadrian's Wall East to West.
Great way to spend quality time with them. Not all plain sailing though, I was told my 'banter' was poor by the eldest and couldn't keep up with the youngest....hey ho....
The walk from Porto is very enjoyable. A little gem, I found during my planning for it is The Portuguese Way To Santiago de Compostela, published by FROM PORTUGAL.com, lovely little book.
Our family Camino Primitivo planned for this year is on hold to 2021, all being well.
Enjoy the time with your son, It will be a memorable experience.
Best wishes,
Paul