Where can I download 3D movies for free?

There's this event my school held where each and every classes has to
organize an activity, like for example games and all that. For most of
the classes they all are having a simple stall selling foods like junk
foods or anything they want. There are also classes organizing a
haunted house or whatever, and movie-watching, things like that. Oh,
and games too, simple games like throwing cans and get prizes, ah you
know, the games where fun fairs usually have.

So like, my class is planning to organise a 3D movie-watching. The
event is like in two weeks from now. So I'm just wondering, where can
I download 3D movies for free? We hadn't decide on what movie yet but
yeah, we're planning on that. I know I can buy the DVD myself and rip
it or whatsoever not downloading on the internet illegally, I'm just
WONDERRRINGGG, because if there is a site where I can download one,
then wouldn't that save my budget a little. So please don't bash on me
or anything, sigh.

Oh and also, where can I buy those 3D glasses too? I heard you can
make them yourself, butttt, I don't know? So where can I buy one/how
do I make one.

Thanks a bunch for your help