Here is a beginner's guide to mIRC:
mIRC: Getting Started with mIRC
You may want to see if this works for you. Once it does and you are in a chat channel, then you may type:
/server irc.efnet.nl
then after a lot of text comes up after you have connected to the chat server, type in:
/join #yorkietalk
and you will be in the YorkieTalk chat channel.