Welcome to Gaia! ::

I'd do the first thing lightangle said... Kill the security cameras and all those other things like that! I'd keep the fire alarms though, don't want to burn the place down... I don't want anyone to know it was me that wrecked the store... burning_eyes
After, depending on it I was hungry or not I'd go raid the grocery section. If I wasn't I'd head to the electronics and get into everything, hiding some of it for me to take home later. And then maybe run through the toys, playing with the ones that I feel like, stashing a few of those too. Probably go raid the grocery again. By now having a microwave or two hooked up for use. Then the camp stuff, dragging out a few sleeping bags to stuff into my fort from the house stuff. Maybe a couple of tents on the side just for added decor... And a couple of paintball and aero-soft guns for protection. Play with the intercom, run around with the carts. And probably make a mountain (or a good sized hill) out of all the sturdy things I could find so I could slide down it onto my bed for the night. Then raid the clothes for a new wardrobe... and one more trip to the grocery for a final meal.
But over all I'd make sure that me and my hoard of things were out of site and next to the nearest exit that people (or cameras) won't see in order to get out with everything. I'm lucky I own a car... whee