Carnival Party Ideas?!?

I'm helping my friend throw a carnival party for her sweet sixteen coming up in July. She's having a bouncy castle, a velcrow wall, a clown, a dj, food, popcorn machine, cotton candy machine, and a snow cone machine. We need idea's for her grand entrance, what would be original and unique. Also unique ideas for invitations. and we need idea's for decorations. As well as center pieces for the tables. she rented a HUGE hall in our community so we have lots of room. there's going to be around 50 to 60 kids there. everyone will be wearing bright colourful clothing like neon stuff. So we just need a lot of ideas to make this such a unique sweet sixteen. Your help would be very appreciated. Thank you.