I want to move my forum from PC to Internet. How to do that?
Take a backup of your DB, open it in a text editor that has find and replace capabilities and tell it to replace every instance of "localhost" with your URL. Then upload the backup to your host. Then find /inc/settings.php and change your cookie URL. Then upload all of the MyBB files to your server.
You'll also need to edit ./inc/config.php with the new database details too.