I'm trying to fix a website for a company I used to work for. It looks like the CSS has been stripped from the page (won't load in any browser, I've tried multiple), the Wordpress theme I had installed is no longer functional, and the wp-admin login page that used to show is no longer loading - there is an ERR_NAME_NOT_RESOLVED that displays when I try to load the login page, and looking in the console on the homepage shows the same error for multiple elements in the page. I have access to the GoDaddy domain information, and I updated WordPress to the most recent stable version with the hopes it might help. It has done nothing.
I do not have a lot of experience with this kind of development. Anybody have any idea what went wrong/where I can start to troubleshoot and get the site back to normal? Or even just an idea to get me access to the WordPress admin page?
UPDATE: I've found that the website that was previously intact is viewable at old.attorneymediateddivorces.com/ - this is true for all webpage URLS, but the admin logon is still nonresponsive and returns an error (ERR_NAME_NOT_RESOLVED) when I try to log on. The WordPress theme was Zerif Pro - see here https://demo.themeisle.com/zerif-pro/