In order, the core elements of survival are air, water, shelter and food. Water and shelter are interchangeable depending on the climate you are in. Use the rule of dead in three: 3 minutes without air, 3 days without water, 3 weeks without food. In the desert you need water and shade before you need shelter; in the artic you need shelter before you even think about procuring water. Fortunately urban survival is characterized by a density of manmade shelters- in survival situations stay in yours, and if time and resources permit prepare it and defend it. It can be shocking in an urban disaster for people who are used to things like grocery stores and electricity and they suddenly become difficult to obtain.
Two of the most basic survival tools that are used by human beings are a knife and a lighter. These are what I have found to be the most useful tools a human can have on their person in any situation. A well-built knife (not a steak knife or a paring knife) is essential in many situations, from shaping wood, making tinder for a fire, cutting, skinning, butchering, self-defense etc. Go buy a decent locking 20.00 folding knife- as you struggle to get it out of the blister pack it comes in you will think “damn I wish I had a knife”. Same goes for a lighter- If you don’t smoke the odds are you don’t have a lighter right now, and possibly not in your car or home. When the power goes out candles have nice ambience but they are best when lit. Cooking food, boiling water, sanitizing a bandage, building a fire for heat, even lighting your gas stove that won’t light when the power is out, they all require a lighter. There are many “cool” and innovative lighters out there- I recommend the bulk pack of Bic butane lighters. They work in extreme cold, they work after they get wet, they put out a good flame (those glow lighters do not), and best of all when you buy a 4 pack for a few bucks you will have one when you need it. There are lots of things that are nice to have in a situation where survival might be more strenuous than you’re used to, but I can talk about those later if you all are interested.
Another benefit of having these two tools is that they make your mind adapt to the reality that you are able to take care of yourself- you have the tools. Taking care of yourself isn’t something to fear, dread or avoid. It’s natural, and should be viewed as “interesting and challenging” as opposed to something to be anxious about. You must be able to take care of yourself to be able to take care of anyone else. If you truly want to help your fellow man-be able to care for yourself first. Remember this: If you jump in the lake to save a drowning person, but you can’t swim; you really screwed that rescue up for the both of you.