Use https://drones.enaire.es/ to see where you can fly. Use Google translate on a computer to translate restrictions to English.
You must have liability insurance that covers Europe.
You must display your EASA operator ID number on the drone.
You should have the drone class displayed on the drone, unless purchased before 1st January 23
Avoid urban areas, privacy laws exist in Spain and be careful not to overtly restricted areas. I believe that you can’t overly roads for example and government infrastructure such as pylons or cables.
Stay at least 5 miles from an airport.
Europe has far stricter rules than the UK.
The biggest issue is the lack of definitive rules in Europe. They exist, vary between each country on top of EASA rules, yet websites mostly contain old and outdated information which simply gets copied to other sites.
For example a fireproof label is often mentioned containing your details, but I believe this is no longer required. Although Iceland does need your contact details on the drone.
Information isn’t guaranteed to be accurate on here either
However as long as you are not an idiot, you ought to be fine. Pick rural areas and forget about flying in towns and cities.