TIPS???
As much as I love my GKids... leave the baby home, for you sake as well as theirs.
A 3 month old (A THREE MONTH OLD????) will be in a stroller (if allowed) and nearer the floor, with no air, no views except of legs, in the middle of noise - oh yes, there is NOISE!!! and with who knows what smells abound down there, not to mention germs floating around from the "public". Somewhere in there will be time for a nap (and for the baby, too!) to put your feet up or assess what you've seen; and a feeding (baby, too) and a potty break (diaper change...no comment).
Enjoy the show with your friend, or by yourself, with all the great suggestions above... decent shoes, backpack, limit buying, camera or camera-phone, handy purse for business cards and money/credit cards, etc.It will be a long day! or at least a few hours.
Good luck.