I need help planning a small farewell party!?

My Mom's best friend is moving to another state, so we invited her over tonight along with two more close friends. The four of them are spending their last night together before she leaves, so I wanted to do something special for them. How can I surprise them and make them feel like they'll always remember this night? I need help with decorations, food, music, and everything else that makes a good party. I'm fourteen, so I can't go out and drive anywhere to get stuff. Please help me! They'll be here in about 3 hours. Thanks!