Ok, after seeing tv shows with end of civilization scenarios it gets a bit annoying to see obvious stretches of reality. First off, supermarkets, Most food will last only 2 years tops. So after that time period you best learn to hunt and fish and grow your own crops. Which is why it is useful to start a new society near a hardware store not a supermarket. Secondly, gasoline and oil. It won't take long for gasoline and oil to breakdown. In storage tanks Gasoline separates and oil can pick up forms of bacteria rendering it inert. Electricity, ok possible but you need an electrical engineering degree to keep whatever plant you have going plus it better be hydrothermal or hydroelectric to keep the power going. Animals, most animals without humans would either die cause they are locked away or revert to their primal instincts. In other words Sparky and the other neighborhood dogs don't see you as a friend they see you as their next meal. Thus pack mentality on larger dogs. Horses, without gas to run vehicles Horses would be the real means of getting around. Anymore stretches of reality with the end of civilization? Personally, I see a year maybe two tops before people are forced to rejoin in a society or face extinction? Basically the 1800s all over again.
In fiction, Earth Abides deals with the food spoilage problem, but also the issue of out of control rodent populations emptying out supermarkets very quickly. Other novels deal with the issue of gas going stale. I liked that Mad Max Fury Road included a post apocalyptic oil refinery.
Oh yes, everyone remembers the great human mass extinction of the 1800's. It was a somber time in history.
The important thing to note is that we can't prevent the fall of civilization from coming, it's like the Grinch's Christmas. So you just have to roll with it, and by "you" I mean the 5-6% of humans who survive the collapse.