There may already be a "slush-fund" for your school into which you could put any profits acquired by you fundraising activities, this would alleviate the necessity of establishing a brand new 501c3. There are, typically, " Umbrellas" under which school activities can be organized. Remember too, if someone receives anything in
return for cash, the cash is no longer considered a "donation" which frees up a lot of activities from certain accounting nightmares. Why not host a dance/rave on
stage? lots of light, good sound
system, Just be sure to rope off the pit, and have plenty of chaperone's in the wings. We did a few dances on
stage in HS and they were quite popular. Another one might be to host a, now hear me out, "movie night" if you have a
screen and a
projector. There are several places from which you can rent "classic" movies charge a modest fee, sell a lot of popcorn, make a lot of Profit. As
Gaff said another great source is to do "royalty free" works, a great one is to offer a good old fashioned Melodrama.
Stage it outdoors somewhere, where kids can
throw popcorn, and act like they do at the movies. Charge a couple of bucks and get any "production costs" donated. One school here, makes their yearly "
nut" by only charging for the spring musical. They made enough to hire a teacher part time, then a TD, part time, and now both the TD and Teacher are full time. Once the District realized how invaluable having a TD was and how much the community wanted the Arts, they couldn't say no to hiring them.