Food and water
Water: each person will need a gallon of water a day. thats alot. you can get some water from the canned foods you should have stored, but it wont be enough to survive. thats where those water purifying tablets comes into play. you can also use iodine or bleach , just not so much you poison yourself, about a tablespoon per gallon. if you end of on a boat in teh middle of the ocean, dont drink the water straight up. but you can dilute it with fresh clean water to make it spread. it will becaome more of an electrolyte drink.
food: you can live alot longer without food then water, but when you are running for your life, calories burn quick and you need to replemish. mre's are a good option and they dont taste that bad. you can also get those calorie bars packed with 1000's of calories. dried fruits adn nuts may seem like a good choice, but its not. dried fruit has lots of suger. too much sugar sould led to a crash later, you diont what the crash to happen right before the zombies bust donw the door. and nuts are a no go because people can have nut allegies. and you may not have one now, but you can develope one. do you really want to deal with a nut allergy? freeze dried foods are a good option adn they have a long shelf life. canned foods are a great option, but can be heavy adn weight you donw, remember to travel light. learning to hunt can vastly improve your chances of not starving to death. hopefully you will be able to make it somewhere safe where you can perhaps grow crops. so having some seeds on hand wont hurt.