how to keep songs on ipod when syncing with new

Greetings, and welcome to Apple Support Communities bailey4ever,

From your post we can see you're receiving an alert that your iPod will be erased if you sync it with your computer.

This would be correct if you've synced this with another computer. We’d like to offer up these resources: 

Intro to syncing in iTunes on PC 

Sync iTunes content on PC with your devices                                        

Change how syncing works on Mac 

While you didn’t mention whether you’re using a PC or Mac.  The first article has a lot of good information! It goes over what happens with syncing, and lets you know about selecting manual as an option for syncing, because you might have more than 1 iTunes library.

The rest show you how to set up manual syncing with either a PC or a Mac.  Please make sure to check all the articles we've provided first, then set up your device.

We hope this helps!  

bailey4ever,

You're right, you'd want to select to manually move your music by only selecting the music you'd like added, instead of syncing your entire library.

Don't forget if you have music purchased through iTunes, you can add these songs to your iPod too: Redownload apps, music, movies, TV shows, and books This might be an additional way to add music on your iPod so you can enjoy using it even more.

Have a fantastic day!