dns - How to connect a domain name to a host?

I have register a domain on internet like domain.com. I have a server on internet which have installed bind9 service on it.

I have enter my name server on DNS tools on my provider domain name manager panel as an A record like n1.site.com and ns2.site.com.

What should i do to connect that domain to my host myself?

You have the domain registered with a domain host service or provider or whatever you call them. Godaddy and Networksolutions are examples. That provider should have a DNS tool where you can set an A record for the domain, that points to the IP address of the server. If the provider does not offer this service, move you domain to another provider that does, or ask them to set the DNS. I prefer if I can do this myself, and most providers offer this service for free.

If you want your domain name to point to your server, you need to update the A record

So, the A record should point to an IP address (unless the domain name you enter is correctly set up of course)

The MX is for email.

I normally leave the others alone.

However, if you've updated n1.site.com (often called glue records) from the original value then you'll have to set up the DNS yourself on your server.