Caution
Check the batteries, the remote and the gas tap first. If the pilot lights and the fire does not, or it will not light at all after two tries, stop and call a Gas Safe engineer.
Low risk
Constant clicking from a hob that is off is the igniter sparking by itself, usually because water or dirt is on it. Switch the hob off at the socket, let it dry and refit the burner caps.
Check the cooker's gas tap and the other burners. If the oven clicks but will not light, or goes out when you release the knob, stop and call a Gas Safe engineer.
Describe the job and get a fixed price from a local gas engineer.
