Not just the school but everything and everybody would float about.
Unfortunately brick buildings stay upright because they are built vertically and gravity pushes the bricks hard on top of each other. Without gravity the bricks would begin to start breaking away and the whole building would start to fall apart. Luckily, because the school would be now in zero gravity, you wouldn’t need to worry about a brick dropping on your head!!
If there were no gravity… we wouldn’t be healthy for long! Astronauts can only stay in space for a year or so before there bodies start to break! So no gravity sounds fun but it could be nasty in the end!