old website to new website
First thing you should do is contact your web hosting provider and see if you can go back to working copy of your website. After you have a working copy of your website download that into a local environment. I would recommend to this either a Mac or Linux machine (ubuntu os what I user). 

Once you have your local environment you can start trying migrating from D6 to D7. You should never try an migration a production site.

From here you can use drush sup to upgrade your website. After your website is been successful upgrade from D6 to D7. You should consider uploading that to your web hosting provider.