As I've experienced it, there are three ways to get all the necessary components to make a VN.
1) Possess all the requisite skills yourself. At the bare minimum, you'll need to know how to write, draw, and program. You don't need to know how to compose, being that there's a ton of freeware music on the internet, but it's a plus. Definitely the hardest route to take, but also by far the cheapest.
2) Know people willing to do work for free. This one is going to require you to have some good friends with a genuine investment in your idea; you're very unlikely to find random, skilled people willing to do work for free. Myself, for example, I have a friend working on my game with me who is both my co-writer and the game's main programmer. She's totally down to work on the game for free since it's a shared idea between the two of us, but we've commissioned all other aspects from various sources.
3) Commission the pieces of your game (artwork, UI design, music, programming) from outside sources. Costly, definitely, but if you have confidence in the people you hire, this is the most straight-forward path to making a quality product. People are infinitely less likely to disappear at random or phone in poorly-made work if there's money on the line.
Of course, there's other factors to consider; whether your game will be free or paid for, whether or not you use a crowd-funding service, additional features for the game such as voice acting, so on and so forth. I can't offer much advice in that regard at the current moment, but it's something to keep in mind.
