What are you looking for?
"What is the best linux distribution for server"
Best is a subjective judgement. The best Linux distribution for server is the one YOU like and which suits YOUR computer. My opinion my differ from that.
It is a bit like asking:
What is the best car?
What is the best sports team?
What is the best religion?
You can get many different opinions, but only YOU can answer the questions for YOU.
"how to configure it?"
What SORT of server do you want? A webserver? A mail server? Something else?
Why nor have a look at: