IRC (Internet Relay Chat) is one of the main communication channels for open source projects. You can freely join a channel that suits your interests if you are looking for help or interested in contributing. A page about contributing to any open source project will typically have its IRC channel listed.
Lurking is perfectly fine on IRC. Don’t hesitate to join an IRC channel. The etiquette of IRC is such that you don’t even need to say “hi” when you join and you can lurk in the channel for as long as you’d like unless you have a specific question or want to share your view in a discussion. So just joining a channel is pretty non-committal.
Provide all the info when asking a question. You can always ask a question on IRC and you don’t need to ask if you can ask a question. Instead, go ahead and provide all the details relevant for your question. For example, if you have a build problem, you can put the error message into an online pastebin and post the link in the IRC channel, asking for help.
It’s not you, it’s the IRC channel. Don’t be put off if no one answers your question. It probably means no one knows the answer and no one feels responsible to say that they don’t. It’s possible that the one person who would know the answer is not online or is busy. Stick around for a while. Get a sense of the channel’s activity. Try asking your question when the channel seems livelier. In the meantime, look for an answer on the web an extra time.