This is kinda hard if you don't even know what an FTP program is (sorry :().
Perhaps you can ask your provider first. Since they speak German, it will be more easy for you to understand.
In short:
for a website to work you will need to upload files to your hosts server. You should have received FTP login details. Uploading these files can be done with any FTP program, just download a trial or free one (search with Google for this).
Once uploaded follow the complete instructions from the Wiki, like Corey mentioned.