How to know if I have activated Cloudfare successfully?

DNS changes usually take 24 to 48 hours to fully start working but it still doesn’t work, perhaps you can use the Cloudflare Diagnostic Center. I also found this tool that check if your website is using Cloudflare DNS / CDN/Proxy / SSL. Otherwise, there is a similar topic on their forum that explain how to verify it using http headers.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)