I'm not a mod, but I should be
You can only create them in the Wrestling Forum and the Test Forum(maybe also the divas forum???) there is an option when you press "create Thread" that says post type, the options are 1) Normai 2) Poll 3) Game
Choose poll then follow the intrustions from there.
IF you want a poll in any of the other forums just ask your local friendly mod to move it there.