Go out and buy loads of glow sticks. Hire a number of “UV Black Lights”. Get all the teens to come dressed in white and have a massive dance party with a live DJ dropping the beats at the start of your meeting or run an afterparty at the end. A great addition to this night is to run a UV paint fight. This is really dependant though on the space you are using and whether or not you can get pain on things. If you are lucky enough to be able to run a paint fight it’s definitely worth doing.