One of the thigs you could do is have all your friends over (boys and girls) and have a dance party. Listen to all your favorite music and serve your favorite snacks. Set up tables where your friends could sit down and relax while eating food and drinking your favorite types of drinks like soda. Put cheap one time use cameras on each table so guests can take pictures. Also have an area where they could go and relax. In that area put comfortable bean-bag chairs, butterfly chairs, etc. As for decorations go put up christmas lights, colorful rugs, and whatever else you can think of. Hope this helps a little.