Basically the title, you need to use the skills you have now and be a productive member of society.
I don’t mean go back and show the wheel or try invent germ theory etc.
For example I’m a mechanic i think I could go back to the late 1800s and still fix and repair engines and steam engines.
Maybe even take that knowledge further back and work on the first industrial machines in the late 1700s but that’s about it.
Great question.
In culinary school there is an entire module on butchering - mammals, birds, fish, etc. I’ve always said my ability to cleanly and safely butcher all the things would make me very valuable in a post-apocalyptic scenario.
Creating and maintaining a fire isn’t easy but it also isn’t hard. Unrelated to culinary school, I’ve learned the skill to create charcoal from solid wood in a primitive low-oxygen furnace - that would be useful.
Even without metallurgy, I could probably cook on slates and stones, or create pottery solid enough to boil water. If I’m around during or after the Iron Age, I’ve got all the cast iron I could want.
Ingredients would probably be limited. My knowledge of food chemistry would definitely help. Without refrigeration I’d have to rely heavily on pickling and salting. If I could learn glassblowing, we could move on to canning as a preservative.