That message means that you are trying to sync with other than the one syncing computer/iTunes library that you can have. You can sync music and videos from other than your one syncing computer/library if you sync you device manually. See:
The thing is I haven't tried to sync with any other computer besides my own. Using the same computer, some iTunes, and same Apple ID/info. So I don't understand why it's saying something about me trying to sync with another computer. [(Sidenote) One day I was messing with my iPod and had to master reset it (Restore Default or whatever it's called) and then I had trouble with the backing up because of computer storage issues. My music syncing problems started right around there, so I don't know if any of that affected it or not.]
When you "master reset it (Restore Default or whatever it's called) and then I had trouble with the backing up because of computer storage issues." you undid your computer being your syncing computer.
If all the synced media like apps and music are in the iTunes library, do the following to make the comnputer your syncing computer
- Backup the iPod to the computer
- Restore the iPod from that backup
How for both is included here:
But I did all of that. Or at least I think it did. I mean I have my iCloud and PhotoStream set up after the master reset. And ever since that little mishap I have made sure my iPod has been backed up on my computer. All those have been taken and maybe even repeated to make sure. But I am just so confused on what I did wrong for my music not to sync. I mean I still have my videos I put on it and the iCloud works just fine.