I seemed to have stuffed up my outlook! Please help!

Ok, so I recently got Outlook and was yet to start up an account until I decided to try and set up my school email account (which is a microsoft exchange account) but, in the process I seem to have done something wrong and I can't do anything with Outlook. Every time I open it, it requires the email credentials that I used during the setup and after I do that I get a message saying 'The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action.' After I press OK for this message, a box comes up with a 'Microsoft Exchange Server' box and and 'Mailbox' box to fill in. I don't know what to do at this point and so I just click OK at which point, the first message re-appears. Then a message appears saying 'Cannot open your default e-mail folders. The file C:\Users etc. etc. is not an Outlook data file.' I press OK then and the program shuts.