Will you partition it off for different stages or use as a lung room with tents? I'm a bit concerned for you regarding your electrical circuitry.. Have you considered your total fully operational current draw or wattage use you will have? By your outline I see the need for 1 20 amp circuit and at least 1, preferably 2, 15 amp circuits run to the breaker box assuming you have the space for minimum 2 new breakers in the box. I'm not trying to be a know it all here PL, If you already know this stuff please forgive me. I've done many home construction projects including electrical that I always made sure was up to code for safety sake. OK? I could tell some horror stories but I won't. Best of luck with it sir. You'll have fun just in getting it all working together!
Sorry for the gloom and doom.