The answer to 'my ceiling fan installation won't turn on' is that there could be several common causes, such as a tripped circuit breaker, loose wiring connections, or a faulty wall switch or pull chain. First, check the circuit breaker to ensure it has not tripped, and reset it if necessary. Next, inspect the wiring connections at the ceiling junction box and the wall switch to make sure they are secure. If the connections look good, the issue may be with the wall switch or the pull chain mechanism on the fan itself.
If the basic troubleshooting steps don't resolve the problem, it's best to call a licensed electrician to diagnose and repair the issue. Attempting electrical work without proper training and experience can be dangerous and may even cause further damage.