Qualifications
Most employers will want you to have a bachelor's degree, likely in a related field such as business or finance (source). There are exceptions and ways to sneak in the back door—for example, this is one of those jobs where you may very likely start out doing receptionist or secretarial work and then your company, if they like you, will start training you from within or foot the bill for classes. Don't strive for the receptionist route—you may just wind up answering phones for the next fifty years—but it does happen.
Also, you must be licensed to sell insurance; sometimes multiple licenses are required if you're selling different types of coverage or if you sell insurance in more than one state (source). This is a good thing, actually, as it gives you more pieces of paper you can hang up on the walls of your office so that you come across as more intimidating.
Oh, and you should look good in a suit.