osufocus :
They just don't connect personal equipment to my school district's network. Never really pushed for an answer for why that is. I have always just used a USB connection. My wifi router does not have connection to the internet, just the printer.
Adding an unauthorized wireless device creates a new avenue of attack for someone trying to hack into your network. That's why IT departments are very strict about allowing wireless printers, and especially wireless routers or access points. Yes it is a fireable offense in many organizations, since a misconfigured device like this can expose the organization's entire internal network to the world.
If you've got your own WiFi router not connected to the school's network, just the printer, then yes you might be able to use the printer that way. But it would still require the approval and cooperation of your school's IT department. The moment your laptop connects to both your personal router and the school's network, it becomes a potential gateway between the WiFi on your personal router and the school's network. An attacker could hack into your personal WiFi network, use that to get into your laptop, which then gives them access to the school's network. And to your IT department that intrusion would be indistinguishable from you using your laptop to access the school's network.
Is there some reason you can't just plug this printer into your laptop via a USB cable? The problem is that you're trying to use WiFi. Most IT departments don't have a problem with using USB or LAN cables to add devices.