@smart51 above is correct with his next step diagnosis.
Here's a little bit more detail to help you understand what you are doing, and what should be happening.
The coil has a big cable from the top that goes to the centre of the distributor cap. That as you know takes the high voltage spark to the distributor. The coil also has two low voltage connections, one is fed 12v when the ignition is on. The other is connected to the distributor.
Inside the distributor is an electronic switch, in place of the original contact breaker. This electronic switch makes an earth path for the 12v, energising the coil. When it breaks this path, the magnetic field in the coil falls, creating the high voltage spark.
So, as said above, first check that you have 12v at the feed side of the coil. If not, go search for it. Broken wire? Poor connection? If there is a capacitor on the outside of the coil, disconnect it. It will be a radio interference suppressor, and when they fail, they can stop the car. With it disconnected, it removes it from the equation.
If you have 12v at the feed, check the other side. That will show if the low voltage coil is ok.
Now disconnect that. Remove the high voltage cable from the distributor cap and either connect to a plug grounded to the block, or hold the cable end close to a good earth, like the engine block.
Use good insulated handle pliers, this can bite.
Do not hold it near a spark plug hole if the plug is removed, as residual petrol fumes might ignite. Rare, but more exciting than anyone wants.
Disconnect the low voltage cable from the distributor. Turn on the ignition. Touch the low voltage cable to earth for a second, then remove. As you remove it, you should get a fat spark jump from the high voltage cable, so be careful not to have moved it away from the block, or that voltage might travel into you. It hurts.
That will determine if the coil works.
If the coil appears good. Reconnect the low voltage cable. With the high voltage cable from the coil still close to earth, get someone to spin the engine on the starter. It should give fat sparks at the cable if the distributor is switching.
If that works, check the inside of the cap and the rotor arm. They get old, and the spark leaks away, so look carefully for track marks.
If the distributor is not switching, check it is rotating, to ensure it is not a mechanical issue, and ensure it is secure, and has not moved. If everything points at the distributor, you may need to contact 123 for help diagnosing it , or for replacement.
