Were you able to use the contact form in it's default state and receive emails? I think it would be best to get that part worked out first.
Did you edit the Universal Email server behavior that is on the page? If so please describe what you did in the server behavior.
As for the file uploads you should go to the bindings tab and expand the WA Upload Files Global Status entry and drag the debug info onto the thank you page then save the page and run a test of the upload. This info should let you know why the file is not being uploaded. If you have trouble determining what the message means post back with what you get from this debug so we can take a look.