Hi there! We’ve created this DNS Quickstart guide for this very purpose - to get you up and running as quickly as possible.
Please take a look. Additionally, we have this Support Guide too that outlines all of our DNS resources. Lastly, there are tons of DNS questions you can access through our search!
If your problem still persists after reading through all relevant guides, please share your account name, the domain you are trying to add to netlify, and any relevant screenshots. thanks!