Carla. Yeah, sure the government will feed us if the economy collapses along with some help from all those third world countries which Western nations have supported during times of famine. You are spot on with your suggestions for water filters and learning about wild foods (solar panels seem a bit out of reach, but there are some directions online for building a solar oven).
About water filters, it is possible that these will need to be non-electric. Have you done any research about this type?
Even if specially packed storage foods are beyond reach as far as affordability everyone probably can at least buy extra cans of whatever is on sale that week. Put some extra cans away for hard times. I make it a habit to do this with buy one get one free canned goods offers. If matched with a coupon sometimes one can really save a lot of money and store food too. During the millenium scare I learned that canned tuna can last up to four or five years. So buy what extra you can afford. Canned meats like chicken and turkey. Spam is an affordable protein source even if not that good. There are recipes sites to make this food more palatable, especially the Spam. In Hawaii, where food prices are very high, the locals have learned to make many dishes, including oriental versions, using Spam. Mark extra cans and boxes with purchase date (month/year) and rotate for use before best by date. There is canned dry oatmeal from Scotland which should last longer than boxed cereals.
Shelf life of canned goods:
Canned Food : Shelf Life - Food Reference Cooks Tips Y2K Kitchen - Canned Food Code and Shelf Life Information Food Storage FAQ - Shelf Life
More on eating wild:
Organica News -- News and Features: RADICAL FOODS—Wild Foods Weed Eaters
A Brit’s blogs about eating wild for a year:
fergus the forager
Some facts about 20th century famines:
The Great Famine-Genocide in Soviet Ukraine (Holodomor) Famine - New World Encyclopedia