Your best option is to use Playlists to manage your music, else as you've found it dumps it in a big heap. You can use the 1-2-3 buttons, once the music has fully been digested which takes a few minutes. If your music has genres then you can sort by that, the List and Music Type buttons both are what I use when playing music off my USB.
Getting your music to playlists can be a challenge; if you're using iTunes either Mac or Win there are two options I've found.
I use an app called DoubleTwist - https://www.doubletwist.com/
Another member also showed me Playlist Export - Eric Daugherty - Playlist Export
- for iTunes, it's is a Mac app but he links to a Windows version too