Might I also suggest at least a 3 month supply of dehydrated/canned/nonperishable foods as a buffer. More would, of course, be better but you'll want some kind of buffer before gardens start producing.

Excellent! But let’s hope the lights don’t go out. Some landlords are ok with tenants creating veg patches. If you or one of your friends have a reasonable landlord, you might be able to start now and get the benefits sooner rather than later. Another alternative that I’ve read about is to see if there is an older person or someone who owns their place but can’t look after it properly and offer to grow vegs in their backyard. You get some, they get some, and the garden doesn’t go to waste.