I’m watching this movie that’s based off of WWII and in the movie there are shops that say, “Jew prohibited” or “Jews aren’t allowed to sit on benches” etc. Are these fictional? Or were they actually real? If they were real, then how could people tell Jews from non Jews? In private, I could understand, but in public, how? A white person could easily go up in public and sit on a bench. Unbeknownst to anyone that they are Jewish. Please explain!
As you rightfully pointed out, people's religion is not written on their face. Despite the fact that Nazi propaganda relied heavily on physical attributes of Jewish people.
The areas in which such pogroms existed (so mostly axis occupied areas, though it seems Italians were not really enforcing such law despite several German requests) usually forced Jewish people to declare themselves by showing it: By law Jewish people had to wear a yellow david star woven on their clothes to be easily identified when on the street. Example of Star
Example of people wearing the said star
Aside from this sign, the religion was written on the ID card of each citizen. Carrying the ID was mandatory and failing to produce it upon request by a german soldier in France could earn you a few days in jail.
Finally, word was getting out easily and denouncing was unfortunately common, whether it was true or not. In that case, (and if people were lucky) an inquiry was launched to figure out the religion of the person. If they were not Jewish, they must have been Christians and they should have been able to produce a baptism certificate. The forgery of such certificate was possible and often offered by priests opposed to the nazis. Several authors mentioned it in their autobiography. Joseph Joffo (Jewish French author) mentioned being saved this way in his autobiography: A bag of Marbles. A failure to produce such certificate without proper excuse would not play in your favor.
Because of the mention of the religion on the ID and the existence of records of people's religions during WWII, creating such records today in Europe is still a very hot and delicate topic. This is why you can easily find stats based on race and religion in the US but not in France or Germany (I'm not saying they don't exist, but they are note as common).
Edit: I failed to mention it, but if Jewish people were to be caught, they would usually face dire consequences (jail until deportation). So eventhough many hid their religion and try or went under the radar, others were too afraid to do so.
Edit II: misspellings and minor details added.