Most outages are site-level. Knowing which you are facing saves a great deal of time.
SIGNS IT IS YOUR SITE
Other sites on the same account load normally cPanel and webmail work The error appeared right after you updated, installed or edited something The error names a file, a plugin or a database It affects one page or one function rather than everything
SIGNS IT IS THE SERVER
cPanel and webmail are also unreachable Every site on the account is affected Email is not being delivered either Our network status page reports an issue
HOW TO CHECK QUICKLY
Try cPanel at yourdomain.com/cpanel. If cPanel loads, the server is running and the problem is almost certainly in your site. Create a plain file called test.html in public_html containing a single word, then visit it. If that loads while your site does not, the server and your files are fine, and the problem is in your application code.
WHAT TO SEND US
The result of those two checks, the exact error text, and the time it started. That turns a long diagnostic exchange into a short one.