Anything new seems hard at first. Along with the help file, click on things to the left of the screen here, like Intro to mIRC etc. There is also the help file and many channels that exist to help with mIRC, IRC, and network specific questions. You can do a channel search by typing
/list mIRC or in place of mIRC use new, or help.
Networks also have websites that give you step by step help with things like registering nicks, help channels, and policies.
Just give it a little time