> I am just an American, but I live in Portugal and it is legally not allowed to film people in public without their consent

If that's actual law that's a bit surprising. In many EU countries there are journalistic exceptions (which may or may not apply in this specific case depending on local law)

> (you also can't have a street facing surveillance camera like in the US)

And same here. Usually the limit is that if you do it within GDPR household exemption then you cannot have it facing street, but if you do it on GDPR scope then you need to fulfill the GDPR requirements (e.g. posting notice, be ready to answer GDPR requests, perform balancing tests for recording etc.).