I’m trying to add the domain graleon.cl to G Suite to use with a E-mail, for doing that I need to add DNS to it, so I’m trying to add the site to my Cloudflare accout and I get that error. (Please correct me if I’m wrong). I paid for the domain yesterday.
Somewhere in the control panel with the company where you registered your domain, there will be an option to change the nameservers.
To use Cloudflare, you need to point the domain to the two nameservers that Cloudflare give you. For example, alice.ns.cloudflare.com and bob.ns.cloudflare.com.
Your domain has to be pointed to nameservers for the site to work. The nameservers are for wherever you have your DNS hosted.
Before you can add your domain to Cloudflare, however - it has to be pointed to valid nameservers so Cloudflare can query then for DNS records. Wherever you host the website should have nameservers you can point the domain to, or other services like the one mentioned by @sandro are available.
Once you have the nameservers setup and you have left them a bit to propagate, you should then be able to add your domain to Cloudflare and change the nameservers to point here.
You will need the ones specific to your Cloudflare account, however you won’t be given these until you can add your domain (and get past the 1049 error). You will need to point the domain to external nameservers so Cloudflare can query them before you will get the ones from Cloudflare to change them to.