Just to make sure, use common tools like the search function (now baked into Cortana, or Microsoft's intelligent virtual assistant), File Explorer, and OneDrive to see if you can find any of your files. Cortana can be accessed through the Task Bar (she shows up as either a long search bar or a circular icon) or by pressing Win (Windows key) + C. The File Explorer can be accessed through the Start Menu (bottom left-hand corner) or by pressing Win + E. You can also go online and look at your OneDrive (sign in with your Microsoft Account if you have one) or through File Explorer. If you honestly cannot find any of your files (I also suggest waiting a day or so to let everything settle in, and conduct a restart or two), then contact Microsoft and tell them immediately of your issue. There's an application built into Windows 10 called Contact Support.