Go to the panel and locate the breaker. The breaker will be the one that is tripped. Tripped means the breaker has flipped to the "Off" position. Cut the breaker completely off, then turn the breaker back on. Push the button on the breaker and the breaker should trip.
Reset the breaker by turning it back on. If this is an arc fault breaker, take the arc fault tester to the bedroom. Plug the tester in an electrical socket and press the button on the tester. The breaker should trip. Go back to the panel and reset the breaker by turning it off and turning it back on again.
Use the same procedure for a ground fault circuit interrupter or GFCI breaker. Take a GFCI tester, plug it into the GFCI receptacle and press the button. The breaker should trip. Return to the panel and reset the GFCI receptacle by turning it off and turning it back on again. If these breakers don't trip, they aren't doing their jobs and need to be replaced.