When you open the Campaign Creator, you need to select the option for City Maps, then open the specific map you want. Once that map appears, you are then in the map editor, and you have to use the tool icons to select resources and then click on the map to place the resources where you want them. Then save the map. After you do that, you will see them available in Open Play for that map.
Expand your fun by downloading free
custom campaigns for Emperor: Rise of the Middle Kingdom.
Visit
Zeus Heaven to expand your knowledge of Zeus and Poseidon.