How can I make a coupon pop-up when they enter our store front? I thought it was Autocoupon with priority "1"?
You are correct. Autocoupon with priority 1 creates a coupon that pops up when someone enters the store. Note that it will only pop up one time per person (you wouldn't want it popping up every time they go to a new page, for example). So clear your cache and cookies between tests, and you should see it.
If you are running multiple coupons simultaneously, please read the "?" tooltip next to the autocoupon field carefully to understand more about Priority numbers and Priorities of coupon applications in general.