It will be 2 years until we can say we are post covid19, if we are lucky. That will mean we have a tested vaccine against the initial virus, we will understand so much more about the virus and whether it has burnt itself out or is able to live in pockets of the human population and respread or mutant just enough to need new vaccinations on a yearly basis (like influenza flu). There are also questions about whether people who have survived a infection are immune to reinfection. Another big question is how bad second wave infections will be, either after the initial lockdowns are lifted or this coming northern hemisphere fall and winter seasons.
1 or 2 years is enough time to change habits and society. Using the September 11th attacks as a similar event, the airport security processes (theatrical or not) , would have been unthinkable prior to that date. A singularity, if not a technological one.
So want follows is my guesses on some of the possibilities, or at least open questions.
International travel is currently at a stand still. What would help it recover? Requiring people entering a country to have full and update vaccinations for flu, covid19, and other things (regional specific?) as part of your passport records. I wouldn’t be surprised to see greater medical screening at all borders, airports and travel hubs (even if of marginal utility). Might you also see this in subway and bus stations. (and other large public gathers), similar to existing metal detector or security checks?
Aircraft manufacturer Boeing seems to be in a very bad place. They were already in difficulties with the 737 Max crashes and the debacle of their response. The global passenger industry is going to cool existing and new order for many years.
Facemasks are likely to become much more common and acceptable in the Europe and North America, as it is currently in the Asia. Look to facemasks showing up on the runway. Another driver will be the push back against facial recognition. (Adding an infrared shielding layer, as well as a dazzling layer)
Streaming services were already “the future” but this has accelerated their domination, as Cinema will be out of favor for a long time. And big film production companies are going to have to rethink their release schedule and distribution channels. (Disney’s timing is perfect).
How long before many of us will be comfortable in crowds of strangers? How will this effect (non e) sports, live music, big concerts, mega churches, theatre?
This will be a big boost to eSports. As will YouTube style of creation and production.
Universal Basic Income (UBI) and improvements to minimum wage will get a lot of discussion and experimentation. Having praised not only doctors as heroes and essential workers, but also cleaning staff, and grocery works, politicians will be asked to explain why the same people don’t deserve a dignified living. This counters several decades of “cheaper at any cost” . There have been UBI announcements out of Spain, and Scotland.
Another side effects will be some rethink of global supply chains for at least some products, especially Personal Protection Equipment (PPE).
The effect the global shutdown on pollution might be a big boost to efforts to improve the environment and address global climate change. Also given the sums spent by at least some governments thy will have to explain why similar sums cannot be spent in climate change before it becomes an cashitropic. Although, arguelly the need for pandemic actions and spending did not become obvious until it was upon us, so this might mirror acting too late for climate change as well. Given the action, sor lack of,  the UK and US governments, this is worrying.
Watch out for calls to return to austerity budgets similar to the 2008 financial crisis (we can’t afford UBI / Living Wage / Carbon Tax / Climate Change until the … -some future time ) .
There has been at least some discussion in Canada that before the social distancing and shutting down of non essential business could be recommended, that the public needed to be onboard. But messaging lessons can be learned and applied to the Climate Crisis.
Work from home has been accelerated for many white collar business and industries. With negative effects on micro-nanagers and commercial real estate.
Distance learning is similarly getting a boost. For both remote working and remote teaching and learning, cases there should be many best practices emerging.
Certainly social networks and video conferencing applications will benefit from a halo effect. Although those that fail to live up to expectations will see a harsh backlash. Challenging when your demand goes hockey stick. Ecommerce and food delivery apps/platforms are equally seeing huge spikes as well. It will be interesting to see if Famers and farmers markets go to a direct to consumer model.