Your best bet is to take care of your financial self. You should do all of the usual stuff, save as much as you can, build an emergency fund, plan for retirement etc.

You are a little young, but you need to sit down with your parents and clarify what they want and expect. Where their wills are, who has power of attorney, any insurance policies, where is the money is actually at. You need to get a sense of their plans and hopefully this might ease the burden you feel. Your parents are adults and will make their own financial choices. You cannot change this. Talking this out with mom and dad might help you realize they are in a better place then you might think. Break the ice by asking for advice about retirement plans whenever you get your first job. Parents tend to be more open about explaining what they did and how to a child that is looking for "help" then a child asking for financial replay of the last 20 years.

You will hopefully find that they have a moderate amount saved up for retirement and they are now doing activities that they have put off for a time. No matter what you discover you must remember that your parents finances are their own and separate from yours (As long as you are not cosigning any loans). This is 100% to your advantage. This means that even if your parents go completely broke your pile of money remains untouched. And you can offer them a place in your home and food in their stomach. This means you must build your own fiances SEPARATE from theirs if you want to provide them with a safety net. It sounds like you have fairly sensible parents so this is likely not going to be that much of a problem.

Once you find out their actual situation (If you can) then you can put in place more targeted savings and financial goals. Otherwise try to get them to put down their wishes and plans in writing if they won't tell you what they are, and get them to put it somewhere accessible so you can help out if they get sick. But mostly, your parents are adults and will make their own choices whether you like them or not.