Make sure your plan on SiteGround includes the staging option or you can consider an upgrade. Right now we’re running great promos.
In Site Tools > WordPress > Staging you can then automatically create a staging copy of your website on a subdomain. Point that subdomain from Cloudflare to SiteGround, configure an SSL and the setup will be completed.
Our team would love to assist with the exact steps, please contact us from the Help Center: