WilI make it i I'm an only child, a female & if one day, my folks are gone? I'm scared. What to do?

I'm a only child and in my late twenties. If myfolks are gone on day, will I be able to survve and be safe, alone? I'm afraid and feel tha if hey're gone, I'll be ol and alone. I don't have a guy or anything. Thus, how can I survive and be mentally/physically well and safe, even if Ido not marry? Wat d you think?