please can someone tell me how one gets on to Cleopatra or is t only thru a progress of missions. I can only open Pharoah.

I don't understand your question. Do you mean how to progress from the Pharaoh to the Cleopatra missions by era ?

I have the same problem - I can play Pharoah but the Cleopatra add on I can't find/load to add to play the additional cities, etc. Where can I find the Cleopatra add-on to load it and play it?

If you have the GOG.com version, you already have Cleopatra. Just select one of the campaigns in the Choose a Mission section to play them.

Alternatively, I understand that within the campaign the missions come at the end, after the Pharoah missions. As has been said, though, you can play any mission at any time by not playing the campaign.

And yes, as others have said, it's all in one application.

Incidentally, if you have any future problems you'll probably get a faster response if you tick the box making the topic a question.