If you're near retirement age, retired, or help those in that age bracket (generally age 70 and up), the preparations you may need will be different from the preparations for a minor or a younger adult. If you're still able-bodied, that's awesome and makes it easier. Even if you're no longer fully able-bodied (or perhaps you never were, people with a whole variety of congenital disabilities are living longer), there's still a lot you can do, or someone can help you do so you can not only survive, but even continue to thrive in the event of emergencies and disasters.
Really, some of these suggestions are good for everybody, and a lot of the ideas and suggestions for senior prepping are also good for people who live alone.
Take your name off of all public places - mailboxes, voice mail, trash cans, wheelbarrow... Place the address (mailbox, trashcan, wheelbarrow) or phone number (voice mail) on it instead. That keeps people from pretending they know you. I know I'm more willing to open the door to someone who appears to know me or claims to know one of my children. That can lead to a scary home invasion or worse. There's been a recent rash of that in another part of the city and there's nothing to prevent it from moving into my part of town.
I do have Itzl and Xoco who will alert me if it's a friend or stranger, but not everyone has Itzl and Xoco type dogs to take care of them. Eradicating your name from publicly accessible places and items just makes sense.
If you, install a locking mailbox so your mail is protected - the mail carrier will have a key to unlock it to retrieve out-going mail. I know mail is supposed to be federally protected, but that doesn't help if your new credit card is stolen, or your private mail read. Or don't have mail delivered at home. A P. O. Box is a good idea if you can afford it. It gets you out of the house, too, if you're retired and don't have any hobbies that pull you away from the TV. Plus, it gets you exercising, an important thing to do so your circulation doesn't get sluggish or "bed sores" form from sitting for too long.
If you're still working, maybe you can have your mail delivered to work. That's what I do. All my mail comes to my work address.
If you don't have a P. O. Box and you're not working and don't have hobbies that take you out of your home, consider volunteering. Not only will this keep your mind and body active, it will give you a network of people who will expect you and if you don't show up, they can look for you - a good idea if you fall and can't get help.
Fix or have fixed anything that can cause a fall. Install hand grips in the tub or shower, place non-skid mats under throw rugs, tighten loose rails on stairs, that sort of thing. Keep extension cords out of your walking areas, they are a trip hazard.
Do a written and photographic inventory of your home. Everyone should do this anyway. Update it when you make changes - buy new furniture, change out electronics, move, whatever.
Have your doctor's name written down, along with your medications, dosages, diagnosis, and a list of contact numbers. Keep it in visible locations and keep it on a card in your wallet. The fridge, inside the front door, by your bed, by the sofa, inside the back door, in the car... Another good thing for everyone, not just seniors.
If you need a DNR, post it with the medical information. Make sure your doctor is aware of your DNR and that it's part of your medical records.
Make sure your fire alarms and extinguishers work.
Put together a "seniors club" of other seniors and single people in your neighborhood so you can check on one another in case you aren't seen for a while. Have a regular meeting time or a regular time when you go outside to be seen so they all know you are OK.
Keep all your medications in a portable, lockable, water-proof container that you can grab and take with you in an emergency and try to keep 90 days of medications on hand if you need chronic medications. Evacuation centers won't have any way to replace the medications or fill prescriptions.Also, double-check any medications you take so you don't accidentally take the wrong ones. If you take a lot of medicines, a daily pill dispenser might be a good investment.
Make sure your Will, Power of Attorney, Medical Power of Attorney, and Living Will have all been recently updated, along with any other essential paperwork relating to your estate.
Keep a list of all the bills you pay each month - to whom and when and how much. Review it occasionally to make sure you aren't paying for something you no longer need - like insurance on a deceased spouse, or a child who's grown and moved away and has their own insurance, or phone lines you no longer use).
Have an attorney and a CPA you can trust to review your legal papers, finances and investments periodically.
Take a senior driving class. Not only will this lower your insurance, they will teach you ways to stay safer as you age.
I feel sad having to say this, but remember how to cross streets. Cross at corners or crosswalks, with the light if there is one. Don't jaywalk, cross from between parked cars, or sprint into moving traffic. I've seen people of all ages do this, but more of them are in my age group than not.
Keep your name and address on or beside your phone.
Rearrange your kitchen so everything is easier to reach.
Keep plenty of easy to cook foods on hand - homemade TV dinners and breakfasts, cans of soup, crackers, peanut butter, in case you get ill and don't feel up to cooking.
Practice your fire drill so you know if it's still something you can actually pull off.
If parts of your home are no longer accessible to you, consider moving. I know, it's hard to give up your home, but you'll be trading it for a home that you can fully access. Isn't that a good trade?
Make a list of community services before you need them - Meals on Wheels, Adult Advocacy Agencies, Senior Centers...
Keep a flashlight and sturdy shoes near your bed, not heels or slippers that can come off if you have to run (as in a fire emergency).
If you need durable medical equipment, get them sooner rather than later. It will make your life easier and the lives of those around you easier. Hearing aids, canes, walkers, and such.
If you are prone to heart attacks, stroke, falls, consider signing up for a Life-Alert program.
Pay bills online and have your checks direct deposited.
Follow the same safety advice you'd give the grandkids - travel in groups, look both ways before crossing the street, avoid alleys and doorways, travel in well-lit areas at night, always let someone know where you are going and when you plan to arrive...
Keep a reasonable stockpile of essential items - toilet paper, tissues, toiletries, so if you get sick and can't get to the store for a week or two you aren't left short.
Practice financial safety - don't co-sign a loan, lend money, give your ATM card or PIN to anyone without a long and well-considered reason.
Connect with the outside world regularly - the internet is your friend, but don't neglect phones, cell phones, HAM radio, even snail mail.
Practice internet safety - don't share your vacation plans, give out your financial info, click on pop-ups, respond to emails from strangers or scammy email pretending to be a friend...
Make sure your address is clearly visible on your house, this helps emergency services find you.
Listen to your body when engaged in sports or physical activity. Make accommodations for your aging if you need to. Don't be afraid to switch to a lighter bowling ball or a small gauge shotgun, or to play in shorter bouts. Drink more fluids - older people sometimes dehydrate easier than younger people.
Check into transportation alternatives before you need them - bus routes, taxi services, senior "access" vans, etc.
If you have specific things you want to pass on to certain people, consider doing so before become too incapacitated to do so or die. This can save a lot of bickering afterwards and you will know that you things were properly given out.
Plan your funeral and if possible, pre-pay it. You'll get the funeral you want, not what grieving relatives cobble together.
Do things to keep your mind agile - crosswords, sudoku, mah jongg... and do them with friends.
If you need some sort of work done on your house or car, take a younger, more knowledgeable person with you if you aren't current on it yourself.
If you are retired and spend a lot of time at home, report odd things happening in your neighborhood - to a neighborhood watch, if you have one, and to the police, if needed. If you spot someone climbing in a neighbor's window, for instance, or a moving van when you know that neighbor isn't moving, for instance.
Stay home if it isn't safe to go out - icy, dust storms that aggravate your allergies.... If you've stocked up on essentials and have plenty of food, you can contact whomever you were going to meet and explain.
Get a pet. Pets provide all sorts of benefits. Dogs especially can help with tasks and serve as an alarm.
If you get a pet, practice good pet safety - keep the pet vaccinated, train them to not be a tripping hazard, keep the pet leashed when outside, etc.
If you or a senior you know is being abused, report it. You (or they) have lived long enough to deserve better treatment.
There's a lot more, but most of those are things everyone should be doing. a lot of these are things younger people might also want to do. Being prepared is something everyone can and should be doing, if only to make their lives easier as they get through each day.