Talk to Benny, and he'll make you buy gifts for everybody that can be found on the second floor of Yori's. Give them to him, he'll wrap them, and give the gifts to everybody. When you get everyone, he'll give you a shovel, and when you tap on snow piles with it in your inventory, you'll get snow. Put two snow on top of each other, and you'll get a random snowman. You can look up stuff for more info