Once you have a clear and useful question, you can start looking for answers. There are two main aspects to seeking new knowledge. One is "what do people know about this?" There are all sorts of resources out there that reflect what other people know, understand, believe, or do. It is possible that you may need to discover information that nobody knows, in which case your inquiry may become a research project - those who have written extensively about inquiry tend to conclude that inquiry-based learning and research follow essentially the same process - but most likely you will find that others have asked similar questions and discovered things that you will find very useful.
The other aspect to consider is "what do I already know?" In order to make sense of "what people know," you have to connect it to what you know, understand, believe and do. You may feel that you know nothing at all that can be connected to learning about music, but if you broaden your ideas about useful knowledge and useful connections, you will find that you do have starting points for your investigation, as well as a "tool kit" of approaches to learning about it.
If you are not certain what knowledge and skills you already have that might help you be successful in your music inquiry, try the inquiry in the Ways of Knowing about Music module. If you would like some practice locating resources and evaluating their usefulness and trustworthiness for your investigation, try the Finding and Evaluating Resources for Music Inquiries module.