If your school blocks VPN connections, that usually means that they’re specifically blocking OpenVPN traffic and/or WireGuard traffic. So if you use a VPN provider that supports OpenConnect (which looks like regular HTTPS traffic over port 443 to your school, there’s a good chance that it will not be blocked.
That’s what I do when I’m on open Wi-Fi networks that block everything but HTTP or HTTPS traffic. It’s not as fast as UDP OpenVPN, let alone WireGuard, but it frees me from the restrictions of whatever Wi-Fi network I’m on.
I’ve placed calls using WiFi calling where the person said they could barely understand the words I was saying due to sound distortion. When I called back over VoIP, they said it was crystal-clear.