Why won't my music sync to my iPod nano?

Hello everyone! I recently bought a used Ipod Nano 3rd generation and was hoping to put music on it; however, every time I upload the music from my music library, it never shows up on the nano. I have tried to sync it automatically and manually with no success. To even get to that point, I have had so many loops to jump through. When I try to restore the device to its factory settings is says the disk cannot be read by my mac (Macbook Pro 2018 15.3.2). When I attempt to sync my music it will tell me my device couldnt be located even though it shows up in both my finder and in my itunes sidebar. I have tried messing with all the settings, re-formatting the disk, and making sure the files are compatible, but nothing seems to be getting me closer. If anyone has advice and even baby steps towards a solution, I would gladly take it! Thanks!

[Re-Titled by Moderator]