As suggested by
@MichaelSG, I think it is a good plan for unexperienced hikers ( ie, me ) to walk the
camino Frances as a first camino experience. But really there is no need of experience to walk the Portuguese route, which I chose (from Lisbon) for my second camino trail. It is certainly different, with plenty of road walking, and way too many cobblestones, but also much beautiful countryside and woodland. I loved it - as I have loved all three of my caminos - each one very different and challenging in their own individual way.
As already suggested, do check out the resources section and take advantage of the creative ways to shorten some of the stages if necessary. But don't fear the route - the Portuguese are the most welcoming people and they will understand any spanish phrases you have, although many will speak and understand English. (I was told by my good Portuguese friend and forum member
@amsimoes that Portuguese TV, which shows a lot of English language programmes and films, do not dub the dialogue into the local language but use subtitles, and so many people learn English this way - please correct me Aurelio if I have got this wrong).
Walking from Lisbon may add to your daily budget if walking alone, because there are some stages without albergues, and so it is necessary to use private hostales or hotels. But from Porto there are plenty of accommodation choices.
I would definitely recommend wearing boots with good, heavy soles and supportive replacement insoles, to protect your poor feet from the dreaded cobbles, and apply some high visibility tape to your back pack and walking poles to ensure that passing cars are aware of your presence on the road.
And if you can organise it, walk the industrial areas at the weekend when the traffic is almost non-existent.
I found a walking partner (via this forum) to accompany me from Lisbon to Porto, at which point I continued alone. There are not too many pilgrims setting off from Lisbon, but it is a route with many, many points of interest and beauty.
Interestingly, on my most recent camino (Mozárabe from Málaga), at one stage I heard a voice that sounded familiar and on investigation I discovered a pilgrim who I had met a couple of days out of Lisbon on my camino Portuguese.
I was aged 60 when I walked this route and my only previous hiking experience was walking the CF - and I encountered no problems.
All will be well - continue to ask any questions here about the route, and enjoy your planning.
I posted every day live from the camino. If you are interested you can see my blog here
http://magwood.me/camino-portuguese/
Bom caminho!