You've paid an insurance company and they've sent you a slip to keep in your car.

If you don't know, it probably isn't. How is it you have a car and don't know if it's insured or not? What country are you in?

First where do you live, and it scares me that you don't know.

At least in the US, if you have a car, you call or go into a insurance office, you pay them for the insurance and they send you proof of insurance and a insurance card.

If you pay the bill on time you are insured, if you don't pay they cancel you

Yeah how do you not know if you have insurance or not? Do you not make a monthly payment? Have you ever been to an insurance place to get it? It blows my mind that you do not know if you have insurance or not.