TEST A BAD BREAKER
Unplug any devices along the problem circuit, turn off all lights, and flip the switch on the breaker. If it resets, you can then reconnect the electronic devices one at time and turn on the lights to determine where the problem is.
Turn off the breaker before plugging each item back in, and then reset the breaker. This prevents a dangerous surge of current should you have a short circuit in a device, which can send a very high amount of electrical current before the breaker trips.
If the breaker won’t reset, test it with a voltage meter. If the meter doesn’t read voltage on the load terminal, even when all known loads are disconnected, then the breaker is probably faulty and needs replacement.