When It Hits the Fan/Rebuilding/Plant crops
When planting crops you first must know how, how long it will take to grow and what should be the expected production and the value (for sale or bather). Crops and agriculture in general works on the rules of economy of scale the more you plant of the same type the more assured you can be of the return you will get (depending of the existence of competition).
Planting crops would be the first step to rebuilding a life or starting over "From Scratch" but it will signify to remain static around a specific location. Crops will be easy targets to people raiding, stealing and you will be increasing your chances of killing or be killed. With agriculture there is also a need to establish some infrastructure, to deal with water and compost.
nuclear polluted environment
After nuclear attack or gamma ray interaction. Take out dirt 5 inches underneath dirt. Put another fresh 5 inches of dirt above original place dirt taken out. Plant seeds, then let plants die only once. Plant new seeds water and feed as you would any other plant to let grow. Over time fertilize crops/plants (Banana peels, apple cores, orange peels, tomatoes. Etc.)
In case of a nuclear winter, it will probably kill any crops and make farming impossible for years.
A person can survive the post nuclear war with the concept of re-construction of the civilization. post nuclear war will take you back to the old time where there was indeed the basics you speak of. If you are NOT SO RELIANT on today's technology than you will survive. Because it gives you time to train yourself for those basics. (that is if the land remains productive)
Lots of people would die from these, only small percentage of the lucky and strong ones might survive (even though living in post-nuclear-war world might not be the best choice).