So, you're in IRC! Here are a few tips:
Why isn't anybody answering me? — IRC is real time chat, but often people have the window open on their computer as they work through the day. Sometimes you get an instant reply, and sometimes it can be an hour or longer before somebody replies. In other words, it's vaguely like sending a text message to somebody.
You can register your user name (your "nick") with freenode.net so that other people can't use it. First, make sure you have your nick set to the name you want to register. You can type /nick xxxx to change it. In your freenode.net tab/window, type /msg NickServ register <password> <email>. For example, /msg NickServ register thisismypassword email@example.com will register your current Nick with the password "thisismypassword" and send a confirmation e-mail to the e-mail you entered. In the future, when you log in using that user name, you'll be asked to authenticate. As you'll be prompted by NickServ, you just type /msg NickServ identify thisismypassword, and you're logged in and good to go!