It all depends on what your needs are. You buy life insurance on wage earners to replace lost wages in case of that person’s death.
You buy auto insurance in various ways (liability, comprehensive, collision) to satisfy state minimums, of course (mostly liability insurance there), but also to replace or repair the car in case of loss due to collision (if it’s an expensive car—you wouldn’t buy ‘collision’ for a beater), and ‘comprehensive’ to replace losses from “other than collision”, including vandalism, theft and other “loss events”.
You buy homeowner’s insurance to protect the value of your home and contents when you buy your home—or renter’s insurance to cover the value of your apartment’s furnishings and other contents—and you buy various forms of liability insurance to protect yourself from lawsuits if you have a relatively high net worth and can be sued for your assets for any number of reasons.
Then there are various forms of business insurance that I won’t even get into. Health insurance, too.
In short, you buy insurance to protect yourself against loss. What do you have that would hurt to lose? That’s what you buy insurance for. A good insurance agent will help to guide you through the marketplace. (And a very good insurance agent will guide you into buying “term” life insurance instead of “whole life”, and help you to invest your savings so that eventually you can even do away with life insurance.) You can look up “whole life” and “term insurance” on your own. That’s your homework.