There are no metal detectors.
There are no pat downs unless your pockets are visibly stuffed or you wear a long coat in.
They will search parcels and packages... because not surprisingly they couldn't care less about weapons-- it's outside food and alcohol they're looking for.
Put your EDC in your pocket if it's small enough--don't wear it to your belt--and you'll be fine. And leave it there... there are panicky North Siders all over Wrigley, and if you pull out your EDC to shift it to a more comfortable location, someone will freak out.
Enjoy the game. You'll love the ballpark, but perhaps the urinals not so much.