Best time to visit 2 weeks in 2 AirBnB locations

Madrid and Bilbao or San Sebastián in the Basque region. These two areas will give you contrasts between the Spanish and Basque cultures.

You really should research Spain to get an idea of which locations might be of interest to you. It’s a large country with very diverse geography. Otherwise people will only recommend popular destinations.

If it was my trip with a car I’d avoid the big cities and head to smaller cities and towns and take day trips, but it’s your trip.

Thank You, That is what I am leaning towards.
I prefer smaller villages so we can walk into town for a cafe or glass of wine. I like historic places, art museum's, wine and olive yards, food is important Tapas and local dishes, beaches, vistas of valleys and mountains, local Art and Music Festivals, Jazz. Late Spring early Fall.
I am not interested in staying in the city but would go to see something Fantastic.

We hope to see two different Spain's in our pace.
Thank You, Ken

A couple places we enjoyed that have the types of things you mentioned are Olite, Logroño, and SOS Del Rey Católico. Knowing nothing about AirBnB, there may not be many in some of Spain’s smaller towns so you may need to look at some smaller cities like Zaragoza, Teruel, Zamora and León, or a larger town like Lugo, Ponferrada, or Puebla de Sanabria. There is no shortage of mostly tourist free places you can visit. With a car there are plenty of sites you can visit as day trips from any of the places I mentioned. Have a nice trip.

Thank you I appreciate your help.

Keep in mind, though, that many of those smaller villages don't have many English speakers.
I have friends in the mostly untouristy principality of Asturias, in the north. It is green all year, mountainous, and gorgeous. But you might have difficulty if you don't speak Spanish. A lot of the tourism in that area is Spanish people, who come to the coast, or to hike in the extensive public lands.

Nancy is right about the lack of English outside of the major Spanish cities. What we have found in staying in Spanish villages is there is always someone who knows some English, often a young person who is overjoyed to have the chance to practice their English. Hosts have become quite good at using Google Translate which also helps. We too are in our 60's and find staying a week at a time in a location makes it all that much easier, you are more of a village guest than a tourist and finally knowing even a little of what I call being polite Spanish seems appreciated.