Chances of actually being pulled over by a police car are slim. Getting caught by a traffic camera is a different story. My last ticket in Spain was in 2017 and it was for going about 5 kph (3 mph) over the limit when leaving a small town. I started the accelerate prior to the speed change sign. Live and learn. Stay at or below the posted speed and don’t speed up until after passing the new limit sign. When I received my ticket it stated exactly where the camera caught me; road number and kilometer marker. I actually looked it up and sure enough, there it was.
Pedestrian only areas are generally blocked off with bollards. Parking areas, paid or free, are fairly well marked. Yes, parking is enforced. It you know some of the places you’ll be stopping, look up parking lots and mark them on Google maps. Use street view to try and determine if street parking is allowed. Generally speaking, parking in small towns and villages isn’t much of an issue. In Spain, once outside of towns, traffic is generally very light.
For Portugal, ensure you know how tolls are collected.