Your laptop will save the last password you've logged in with while the laptop was connected with ethernet
(cable). It saves that information for when you go home, so the connection should work as expected. So the first thing to check is that you typed your username and password in correctly.
If you've recently changed your network password but have not yet logged in to the laptop with the new password while connected via ethernet, you should be able to log in with your old password.
If you've never logged on with this laptop before, you will need bring the laptop on campus, plug in with an ethernet cable, and log in - this will save your profile on that laptop.
For help with VPN issues, see I can’t connect to VPN. What should I do?
If you are still experiencing problems, contact ITS for assistance - How to contact ITS