First time in Spain mid May - first of June

Hmmm.......
Where are you planning on renting a car and for what reason?
Transportation to Portugal is best via plane. However, trying to work in Portugal, a visit to Morocco, other cities in Spain and fly back out of Barcelona sounds ambitious.
You could take the train to madrid and stay there for several nights.
Add another night to visit Toledo via train.
Then take the train to Seville and spend several nights.
From Seville you could rent a car and tour Ronda, Granada and other areas of interest.
Others will need to guide you on Morocco as I have not visited.
Suggest you fly back to Barcelona to catch your return flight home.
You will be visiting during a great time just prior to the onslaught of tourist season.

We spent 2.5 weeks last spring without a car visiting Seville, Cordoba, Ronda, Granada and Madrad where we had intended to day trip to Toledo. This was easy to do -- and we could easily have added a few other stops -- without having a car.

Are you planning to drive? A car is great in certain regions and for seeing more rural areas, but not a good idea for cities. And distances can be pretty far in Spain (ie long drives).

I'm sorry to hear you've already booked your flight round trip for Barcelona. It might have made more sense to do an open jaw flight schedule and return out of Madrid or Lisbon. Backtracking will cost you extra time and money.

Having said that, you can make a round trip by train to Madrid, Toledo, Cordoba, Sevilla, Granada, Valencia and back to Barcelona. That would be about 15 days give or take. No car would be needed or useful.

You could also get a car and drive around Cataluña and the Pyranees, then the Basque region before stopping at points in the Castille region (Salamanca, Segovia, El Escorial, etc...). These are car-worthy areas. Drop the car off in Madrid and return by train to Barcelona for your flight home.

Thank you all so much. The ticket was a gift so we shall make it work! Just to be prepared, I obtained our driving permits as it appeared there might be enjoyable driving time in Southern Spain in the White Hill Towns. Of course, I'm excited at having a high speed train experience so I am trying to work that in with an openness to flying between cities as well. Barcelona to Madrid and then south to include the hill towns and then a pop over to Morocco is a basic route I have but will appreciate any and all advice and opinions. Thank you again.

Thanks for giving some more info. Your basic plan will work very well and is close to the first option I outlined. You can fly into Barcelona and spend about 3 days there. Take the train to Madrid and spend about 3 days there. A side trip to Toledo is a good option. Sevilla is another short train ride from Madrid and you can stop at Cordoba on the way. Or visit Cordoba as a daytrip from Sevilla - it is only 45 minutes by train. Sevilla is another roughly 3 day visit. A car to drive in the hill towns is an excellent idea. You can easily take the ferry over to Morocco for a day or two. Try and fit in Granada to visit the Alhambra - you'll need two days for Granada. From there you can either take the bus or drive to Valencia for a couple days and then train on to Barcelona. Or just fly from Granada to Barcelona. Adjust your times and locales based on your schedule and interests.

Congrats on the gift and the present. My sweetie and I will be in Spain for most of May.

There are great suggestions here. I've also had good feedback on a driving route through southern Spain.

https://community.ricksteves.com/travel-forum/spain/andalusia-counter-clockwise-loop

We're using Vueling to fly from Barcelona to Seville at the beginning of our trip. The reverse would be an inexpensive option for getting back for your flight home. Vueling may even be able to get you to Lisbon.

Have fun! (and maybe we'll see you on the road! ;)

I certainly understand "strong desire to see Morocco" but, before you decide to take a ferry to Morocco for a day or two, read up on it. After researching for my trip to Spain last February, I decided that even with 3 full weeks on the ground in Spain, it wasn't going to be worth it: getting to the ferry and going across to Tangier was going to take the better part of a day each way, and Tangier just isn't Morocco. I could have gone to Marrakesh and Fez, for instance, but the flights weren't convenient for me, and it appeared that getting from one to the other would take many hours. You may have more flight options, since you are going to Barcelona, Madrid and Andalusia and during tourist season.