We are visiting Portugal for the first time in October. We are active 60 somethings who enjoy wine, different cultures and beautiful vistas. Would love feedback on our itinerary, if we should add or change anything.

Fly into Lisbon, immediately take the train to Porto
6 nights Porto with a day trip to Braga/Guimaraes
2 nights Duoro Valley via train to Pinhao-
5 nights Lisbon (via train from Pinhao) with a day trip to Belem /Jeronimos Monestary and daytrip to Sintra
Fly home

If you haven't booked flights already, I'd suggest you fly into Porto. and go directly to Guimaraes (there's a bus from the airport) and spend a night (or two). I recommend the Hotel da Oliveira, right on the main square (there is also a posada that folks recommend that looks awesome, but personally I just loved being right in the old town itself). From my experience, entering Portugal this way was simply magical. Then the train brings you right into Porto via Sao Bento, and another incredible introduction to that city!

Even if you don't do it this way, I think that you could consider just doing Guimaraes: there is plenty to do and see there; you could make a "game time decision" about whether you want to add on Braga. I thought that I would try to get there, but found Guimaraes so enticing that I didn't leave it. There's plenty to do and see on just a day trip (or longer). Just wandering the beautiful town, the castle, the church with a really interesting small museum (right by the main square), the cable car and walk around the boulder fields with a wonderful vista!