Obviously they were affected a lot, but what was a normal day like during that time? What did they change in terms of their work and school schedules? How did the economy fair considering there was also an enormous war going on at the same time. Of course I’m asking in reference to the outbreak of the COVID-19 virus (however it’s not nearly as bad as the Spanish Flu, at least right now), but I am also genuinely curious about that time period.
I wrote before about the impact of the Spanish Flu in Italy. You can find this old answer in this special thread with lots of other contributions - this should get you to the first post of my answer.
I reckon this only answers part of your question in relation to one nation alone, which means that there's plenty of room for new contributions. But I hope this helps!