Portugal itinerary help
 

Is this good fly to Lisbon then to Lagos for 4 nights then Lisbon 4 nights the. On to Porto for 3 nights then home to USA?

From Lisbon to Lagos there is no flight connection. The nearest airport is Faro, which is aprox. 80 Km from Lagos. From Lisbon to Lagos the choices are: 1)By train, check timetable on www.cp.pt ; 2) By bus, or 3) renting a car.
From Lisbon to Porto the best 2 options are: or flying www.flytap.pt or train www.cp.pt
You might check a map to decide which cities to go first. Which city do you arrive and departure from Portugal?

I figured we fly to faro we fly into Lisbon then home from porto

Why would you fly from Faro to Lisbon? You will loose much precious time checking in for your (short) flight, waiting for luggage, etc. Rent a car and drive. Lagos to Lisbon is less than 3 hrs drive.

I would recommend taking a train between Lisbon and Porto. While the Porto airport is quite nice, the Lisbon airport is very large and you will spend as much time in line and pre-traveling as you would if you were on the train, lounging and watching a film or reading a book. Plus the train to Porto drops you in a very nice part of town where you can walk or rail to you lodging, where as with the airport you are farther away.

Additionally, you might have difficulty finding flights to the US out of Porto. You will either have to fly through the Azores Islands on SATA or TAP (portuguese airlines) and onto Boston or New York, or fly backwards to Frankfurt, Zurich or Paris and take a direct flight to the states.

SATA airlines does have occasional flights from Porto to Toronto, which is probably the easiest way to go if your flight times line up and your city in the US is accessed easily from Toronto.

In September of 2015 we flew from JFK into Porto where we stayed for 4 days. We then flew Ryanair from Porto to Faro and then took a shuttle to Lagos. After 4 days we took a train from Lagos to Lisbon and flew home to JFK from Lisbon. All transportation was really easy and relatively cheap.

In design did you like Lagos?