Sorry if this is the wrong forum but I was wondering if it is posible to set a game on an 'auto-play' type thing so you can watch how the civilisations expand without human interferance.

No, there is no way to do what you speak of, but you can load the editor up if you have PTW or C3C, select "Debug" on scenario properties, and generate a map, make one tile island out in the middle of the ocean, put yourself there, and each turn just watch the AI.