In control panel/phpmyadmin, you can import your backed-up database into another database by chosing to "Edit Database" (or similar link), clicking on the "SQL" tab on the resulting screen and navigating to the back-up file. Then click "Go".
the quickest way to find your physical path and get your full site online is to create a new text file using a general text editor (also found in the Useful Programs FAQ). In that file, type the following <?php phpinfo(); ?> Save that file with a name like path.php (use a different name!). Upload this file to your web root using your FTP program. Then open your browser and type www.yoururl.com/path.php (or, whatever your filename was). You should get a page full of information - scroll down the page to the section labeled 'Apache Environment'. Look for the variable DOCUMENT_ROOT, the value of that variable will be your physical path for XOOPS_ROOT_PATH