How can I transfer documents & music loaded from CD from OS 10.10.5 MacAir into new iPad?

iTunes for Windows maintains your Music Library - where a copies of your music copied from CD and other external media reside. When your iPad/iPhone/iPod are synchronised with your PC using iTunes, your Music Library is copied to the device.

As such, if you need to synchronise data or your Music Library, you simply need to synchronise the device with your PC using iTunes for Windows; subject to your settings, your entire Music Library or elements of it will be copied to the new device - simple.

The most recent version of iTunes for Windows supports Windows 10 and 11 - although older versions of iTunes remain available for Windows 7 and 8. The legacy versions of iTunes for Windows still offer full synchronisation services. However, should your newer Apple devices ever need to be restored or updated by the Windows PC, you may need access to the current version of iTunes - this entailing use of Windows 10 or 11.

Use iTunes to sync your iPhone, iPad, or iPod with your computer - Apple Support

Recent versions of macOS have replaced iTunes with the Music App. For mac, iTunes as an App was re-branded as Apple Music. At the same time, iTunes as synchronisation service was subsumed into Finder.