'wrestling servers' where you can 'download stuff'?
uhm,... IRC (Internet Relay Chat
) consists of a network of IRC servers where you can connect to with an IRC client like mIRC. With such a client you can chat in so called 'Channels' with all other people connected to one of the IRC servers in the network you connected to. Read more in the IRC Intro
Special 'wrestling servers' do not exist. And as far as I know there are no wrestling themed IRC networks. (There are gaming and Startrek networks!) But you might manage to find wrestling themed IRC channels on all major IRC networks.
You can see a list of all existing IRC networks
You can search
for wrestling related IRC channels too!
As for 'downloading stuff'; in my opinion mIRC is primarily for chatting, not a file share program. When you have found some friends on IRC to chat about wrestling with, they might have some things to share with you (like photo's or something? I have no idea about wrestling)