kayoo123 That's not how CNAMEs work.
What a CNAME does is, in short terms, show the page that one would find at the URL it is set to.
For example, this wouldn't work, but if google.flarum.org
had a CNAME to google.com
, it would show Google's page.
And as Ralkage mentioned, you need to add your domain to the FreeFlarum settings.