That's not how USB works. USB devices never generate events on their own - you need to find the relevant pipe on the device's interface. Then, you'll need to send requests to the device, and when an event happens, the device will respond.
I suggest reading up on how USB works. Also, if a driver for another operating system already exists for this device, maybe the developer for that can walk you through it? You'll also find that this book for all its faults, does have a decent chapter on writing USB drivers, and explains how USB devices, interfaces, endpoints, etc. fit together.
You might want to look into writing your driver in userspace. Writing kexts isn't really something I'd recommend to novices, and never something I'd recommend if it's possible to do the same thing in userspace.
Finally, please don't expect the users of this site to walk you through the whole learning process of writing a driver for your device. There's a lot of material out there that you can learn from - books, Apple's documentation, blog posts, Apple's source code, 3rd party source code, and so on. Yes, this will probably take you some months. There's no way around that (other than hiring someone else to do it).