Most of us never give circuit breakers a second thought unless they trip. They sit there for years waiting for an overload to keep us safe. But they can fail. If you move into a new house, or if you think you may have taken a lightning strike, trip the breakers off one at a time and make sure that circuit goes cold. Don't just trip the lever off and assume it's cold, go look! If the breaker is marked "Living room lights", turn them on then cut the breaker. Are they still on? You don't need much in the way of test equipment for outlets, just plug a table lamp in. Why? I've seen several occurrences where lightning had welded the contacts inside the circuit breaker, and it will never trip! Two of these resulted in the house burning down from an electrical overload.
Unless you are familiar and comfortable with electricity I would not recommend removing the cover of the breaker panel. If you're in doubt, don't.
Unless you are familiar and comfortable with electricity I would not recommend removing the cover of the breaker panel. If you're in doubt, don't.