Congratulations on your coming retirement. Take it from one who got off the rat-wheel some 12 years ago...RETIREMENT ROCKS!
You just need to find a purpose. Once you get out of bed each morning, each day is a gift to be appreciated and fulfilled according to that purpose. That is why it is called "the present."
In Portugal, many local folks of all ages speak at least a little English (unlike in France, Italy or Spain their prime time TV is in original language with Portuguese subtitles...it helps). The people are exceedingly friendly and helpful. I have walked from Porto twice, 2015 & 2017. It takes about 10 days (+/-). My favorite phrase in Portuguese is "falla Ingles?" (do you speak English?) phonetic I think...
I recommend carrying less than you think you need. Leave out any "just in case" items.
The outfit you wear and one clean change should suffice. One pair of convertible pants (worn) should also suffice for 10 days. If you plan to walk from June to August, go light on rain gear. I now prefer an umbrella stuffed into my sternum strap for short-term showers, with a lightweight poncho packed away for heavy driving rain.
Regarding the umbrella idea, I recently used a very stout and well engineered German-made trekking umbrella on my recent Camino. A fellow pilgrim I met simply pulled out his standard duty Totes umbrella. While I was fumbling with the over-engineered clip-on mount for my ĂĽber umbrella, he simply stuffed his umbrella handle into the shoulder harness where the sternum strap meets his shoulder strap and away he walked...easy peasy.
I was very impressed. Simple is sometimes better. My only additional advice is to test fit the umbrella you might use for sun shade and light rain protection to ensure the shaft is long enough when the umbrella is up and open.
Any well made, reinforced umbrella will work. Aside from shaft length, the key thing is resistance to wind, so it does not blow inside out. Try to test this fitting at home. If you are going to buy a new umbrella I recommend either obtaining one with silver on the outside to reflect the sun, OR a light colored umbrella (powder blue, light green, yellow, etc.). Overall though, I am now of the opinion that umbrellas can be superior to ponchos or rain parkas, especially in light showers with little crosswinds.
Also, if you plan to stay in private accommodations (vs. public albergues) you can ditch the sleeping bag and liner, as linens are provided. Most towns have pharmacies and supermercados (small supermarkets). So, you can buy what you need along the way.
Useful smartphone apps for Portugal include:
- CTT - Portugal Post Office (you can mail parcels ahead to Ivar at Santiago)
- CP - Portuguese Railways (to get to Porto)
- Metro Porto - The Porto Metro System (useful if you want to skip to the edge of town to start)
- Smart Continente - The Continent family of supermarkets, markets and small shops
- My RNE - RNE Bus service, prevalent throughout Portugal
- iThinkdiff Portuguese - Probably the best Portuguese online and offline dictionary, phrasebook I have found.
- Wise Pilgrim Guide - Camino Portuguese - I know the author, who lives in Santiago. These apps are kept updated and are being revised soon to bring vast improvements. I recently saw the beta of the revised version and was frankly blown away. Very inexpensive - like USD .99.
Similarly great smartphone apps for Spain include:
- Correos - Spanish Post Office
- RENFE Ticket - Spanish Railways
- ALSA - largest intercity bus company
- Eltiempo.es + - The BEST local weather. Virtually every names place in Spain and the world is here.
- iThinkdiff Spanish - Probably the best Portuguese online and offline dictionary, phrasebook I have found.
Generally great apps (IMHO) for Camino use include:
Microsoft Translator - Produces better and more colloquial translation than Google Translate, according to my Spanish friends.
Google Maps - Once you are in a town with named streets, this is priceless for getting you to your lodgings or a 'pharmacy near me,' or a 'supermarket near me' fast. Don't forget to change units to kilometers.
Wise Pilgrim Guides - Many & various Caminos - I know the author, who lives in Santiago. These apps are kept updated and are being revised soon to bring vast improvements. I recently saw the beta of the revised version and was frankly blown away. Very inexpensive - like USD .99 each. Also available in a bundle if you plan to do multiple Caminos. I have every one of his Wise Camino Guides. I recommend them very highly.
Hope this all helps.