We have completed a Joomla installation on our dedicated server on Linux/Apache using quickstart with a JoomlaArt template and have been able to manipulate the menus, etc. no problem.

However, we require to set up the Server settings in Joomla's Global Configuration and/or the configuration.php file to allow ftp upload of material to the Joomla site and also allow upload of Joomla extensions in the future.

Unless you are in Root or have Root Access I do not believe that you will be able to change the settings. You will need to contact the host, give them a listing of the changes needed and tell them why.

What type of server settings do you want to change php.ini settings or any other settings?