Thank you!! It's nice trying to help you a little bit and try to find together good places to visit. Glad to do it, with pleasure, and i will love to know the choices you did or after the trip, if you liked it as well, if you want to share your feelings ;)

I've never used BlaBlaCar, but I know people who did and told me that it was a good service, so maybe it could work for you. You can also easily move by bus. The main company's name is "ALSA" and you will find bus stations in almost all big/middle/little cities along your way. Then, if you want to go to a village in the mountains or something like that, maybe it would be harder to find a bus to go and a blablacar driver to take you (i don't really know!) so maybe renting a car could be an option? If so, maybe you will need an International Driving Permit (IDP). I'm not sure and you should find out!

Let me leave you here some places you would maybe like to google too, just to see if you like them and maybe try to integrate into your itinerary. They are some villages ranked like the most beautiful from Spain, and others i like too.

In Salamanca: La Alberca, Mogarraz, Miranda del Castañar, Candelario and Ciudad Rodrigo. A Coruña: Corcubión, Muros and Laxe.