On my thirteenth birthday, I had a sleepover at my house, only we stayed in my parents moterhome, it was like staying in a hotel, my mom and my older sister were really cool about it, they would bring us stuff like it was room service.. I had a blast! but you can also go bowling or go to the pool hall or something simple like that. In my city, there is this huge recreation center that you can rent for the night, there's a basketball quart, a stage and a kitchen, everything you need for a party. Well have fun!!