Moving OpenCart to a new server:
Copy all the OpenCart files from your existing web server to the new web server.
Export the OpenCart database and import it into the new server.
Edit config.php and admin/config.php. These files contain the filesystem paths to OpenCart folders, URLs to OpenCart frontend and admin, and database access details. The paths and database details will most likely need to be updated, and the URLs will need to be changed only if the OpenCart store's domain has changed.