In Settings>>General I am missing some fields

You are in the wrong settings page. Your site is a multi-site setup; the URL is set in the site manager, not in individual sites.

Go to Network Admin/Sites in the My Sites menu:

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Select a site to edit:

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Change the URL:

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Update

You need a subdomain setup to get editable URLs.

See Create A Network for the installation guide and Configuring Wildcard Subdomains for the server setup.

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