Lesson #1: Have a Plan B, because if anything can go wrong, it will. When you’re in the wilderness you need backup comms, back up food and water, backup shelter from the elements and backup protection.
It sounds like you need to treat it like a space mission: redundancy in everything.
In the Before Cell Phones era, there was much more emphasis on being able to operate independently. It was a given that if something went sideways, you were on your own. Getting off trail made it doubly so. The standard advice was to inform a trustworthy person with your itinerary and when you are getting out and supposed to be back. I never did that, because young people never think something bad will happen.
Generally park Rangers will note if someone’s car is at the trailhead too long maybe. One reason for permits.
Today, with easy comms, they get phone calls at park headquarters. “My feet hurt. We’re all out of Pringles. Come get me.”
I like this Anceshntr guy.
In Engineering referred to as Murphy’s Law
In Aviation as “Always Leave Yourself an Out.”