If something inside the fusebox is tripping, there's probably a good reason why. And it's very likely a safety concern. Turn off the circuit breaker and don't use the light. A potential short circuit or overload could be present. Contact a qualified electrician to identify and fix the issue to avoid further damage or electrical fire hazards.
In some cases, yes. While simple bulb replacements might be manageable for DIY enthusiasts, electrical wiring for new outdoor lights, should always be done by a qualified electrician. This ensures correct functionality, longer life, safety compliance and avoids potential hazards. This is even more apparent for lights that are not going on the walls of the property, and where cables and joints are being buried in the garden.
