First of all, I apologize if you needed this answer by last Sunday.
In order to use wifi at Purdue, you need Purdue login credentials so there is currently no way for you to connect on your laptop on campus.
Right now, we also don't have any working guest computers either. Purdue Libraries normally has a couple of guest computers that a visitor could come and use, but they are unfortunately out of order. Once they are operational again, I will be happy to send you the information.