Most local power outages are resolved quickly, but if you suddenly find yourself in the dark and it's safe to do so, check if other households in your street still have power. If they do, you may be the only one experiencing a power outage. Check if your mains switch in your fuse box is off. Turning it back on may fix the problem.
If you believe you have any electrical faults or problems with an appliance, contact a licensed electrician. Never try to fix an electrical fault yourself.