To keep it from turning off you could go to Start -> Settings -> System -> Power -> Advanced and untick (or tick) these boxes as needed.
Secondly, if you go to Start -> Settings -> Connections -> WiFi then you will see where you can pick up WiFi spots and if there are any in there then you can edit those setting but only to the point of the encryption key basically. Keep in mind the 6700 only does 802.11b BTW. But my point is there is no place in there for a UID and Pass.
Now, if your school is running an open hotspot but requiring you to open your browser and login with a school given UID and Pass then all you can do is find what was suggested earlier and get a password manager. You may want to look at
KeePass PPC v0.4.5 or maybe
Pocket Cryptex v1.0