I’m hosting my website on (let’s say) Alpha_Host, which is my registar too. My current DNS points to colin and robin on Cloudflare.
I want to move my hosting to Sitegroud, but since it does not support my local TLD, i can’t move ALL (domain name + files) to Siteground.
My question is this: If i want to move my file to Siteground and keep my current domain with my current registar, what changes should i do to my DNS and where? Should i change DNS on my registar or should i change IPs on Cloudflare?
As your nameservers point to Cloudflare, your DNS will be hosted here. This means you should update the Cloudflare DNS page with the new details from Siteground.
You would typically do a one-to-one match of your DNS records here with the ones at your new provider. The most common exception to this is if your email is hosted elsewhere.