Which is my ID in rise of empires and how can I find it?

Your ID is the name that you are assigned when you start the game or whatever you have changed it to. If you tap your power number (the larger number in the top center of the screen) you will see your 'Lord info' which will tell you your current name and have the option to change it (although this may cost gems).

You can also find the information through the settings menu, account option.