To join IRC you need not have a microphone, just writing skills is all :)
Nowth, that is easy, to keep people from using the name you wish to use, you register it. Names expire after 30 days of non use, however.
Just wanted to also add the channel is created. When i'm in IRC I'm known as Fuzzball (which is mostly true being a cats pet I have a lot of their fur on my face when I wake up)