A broken site can mean many things, but it all boils down to a huge headache. The easiest answer is to post around social media and hit the search engines to find someone who can do an emergency repair on your site and hopefully get it back up and running again. But that only fixes the immediate problem. It would be helpful to not only understand how to fix the problem but have an idea of what causes these errors, some preliminary ways to fix them, and most importantly how to prevent them.