Verified answer

If you are going to be using it in the future it would be better to add the server as direct connect doesn't remember the ip address. For joining the server just type in the ip address in the bar with :25565 added to the end. If this is a hamachi server these instructions will still work but you must be in the server host's hamachi network.

You need the ip for the server. Do a quick google search on ips for minecraft servers.