NSW Can high schools stop you from making memes about it?

[cleetus]

I want to start a meme page on Instagram about my school. I will upload memes relating to teachers and welfare staff and just about our school in general. And of course they will be mocking the school.
Can i legally do this without the school trying to stop me?

There was once a meme page about our school and I heard rumors going around about some guy getting suspended for it or something. Can the school do this legally?

P.S : I don't hate my school, it's just for a bit of banter between the students