The iPod is registered under an AppleID that no longer exists...
I would go here to try to re-activate the old Apple ID (contacting the "official" Apple customer support as needed)
https://www.apple.com/support/appleid/
and the iPod was formatted for Windows iTunes.
If your current computer is a Mac, that (by itself) should not be a problem. Macs can read and write the Windows format used with iPods, and can use an iPod that is formatted for Windows, even without doing a Restore on it.
The actual problem is off-loading songs from iPod to your Mac. Even with your old Apple ID, transferring songs from iPod to computer using iTunes is only for songs purchased from iTunes Store. iTunes syncing is typically in one direction only, from iTunes library on computer to iPod. However, there are third-party methods and utilities that can transfer from iPod to computer. If you do an Internet search on something like "ipod transfer music," you should get some useful links.
After the song files from iPod are on your Mac's drive, you can add them to your current iTunes library. After confirming all songs are there, you can do a Restore on iPod using iTunes on the Mac, if you want it formatted for Mac. Then sync it as desired.
NOTE: If you have songs on it "from 7 years ago" that were purchased from iTunes Store, those purchased songs may use DRM (copy protection). Early 2009 was when Apple stopped using DRM on song files sold by iTunes Store. If those songs are purchases made with your old Apple ID, you'll need that Apple ID and password to authorize your Mac to play those songs in iTunes and sync them to iPod.
