I backed my iPod to my PC using iTunes. Where does it put the backup?

Neither iCloud nor iTunes backups include apps. You can redownload apps from the App Store (assuming they are still available).

Also see the following from About backups for iPhone, iPad, and iPod touch - Apple Support

It lists the things not included.

A computer backup of your device, which is not the same as a sync, includes almost all of your device's data and settings. A backup from a computer doesn't include:

• Content from the iTunes and App Stores, or PDFs downloaded directly to Apple Books
• Content synced from Finder or iTunes, like imported MP3s or CDs, videos, books, and photos
• Data already stored in iCloud, like iCloud Photos, iMessages, and text (SMS) and multimedia (MMS) messages
• Face ID or Touch ID settings
• Apple Pay information and settings
• Apple Mail data
• Activity, Health, and Keychain data (to back up this content, you'll need to use Encrypted Backup in iTunes.)

See information in: Locate backups of your iPhone, iPad, and iPod touch - Apple Support

Sorry, I don't know.