Another beginner question..

I want to set up dns correctly - can someone advise if this is correct please?

add the three ns.names to namecheap

Then what?

Do I add A record in namecheap or on digital ocean dns area?
same with Cname - on namecheap or on here Digital ocean.

If someone could advise exactly what i need to add and where then that would be a big help.

My site will be using https lets encrypt and just a wordpress blog if that helps.

And what if I want to use cloudflare?

Thanks in advance.

Colin