If you don't have dhcp then there is little point looking for dns settings... if we are working with a proxy server you will need to ask the school for the ip address needed eg, 172.168.88.20 and there should be some sort of tech help desk...
...as for upgrading ip4 no but you can temp disable your ip6 by right clicking the network icon for your wifi and unticking the ip6 checkbox... it's always under properites.
That may be what the school wants to get to the net but of course most art programs like Adobe (
anything) assume ip6 to talk to their systems so it's offen catch 22.
I know you say you've tried lots but please also post us a network ipconfig /all and a basic ping test;
[windows key]+ [r] type "cmd" press...