Just a few ideas of stuff you can learn that could come in handy during a societal collapse.
Start learning about homesteading, soil science and sustainable farming techniques. Look up 1 acre farming plans.
Have a look at open source ecology’s global village construction set.
Get into beekeeping.
Learn how to make rope.
Learn how to make a primitive kiln and forge.
Get a guide to edible plants in your area.
Sideways rectal pineapples for that chucklefuck.