Q:Where might their school be located around?
Anonymous
Their school doesn’t exist in actual Paris, like many other places in the series, including Marinette, Adrien, and Chloé’s homes, but we can conclude from a few scenes that it’s right across the Seine from the Notre Dame de Paris:
(Marinette’s house => Collège)
(Collège on the right.)
(Notre Dame de Paris on the left.)
There are a lot of other scenes that depict Marinette’s house right across the Seine from the Notre Dame as well. @paris-in-miraculous-ladybug might be able to give you some more information on this.