iPod Touch Music to Mac and iPhone

I have an iPod Touch which has albums uploaded from CDs to iTunes when one was able to do so, about 13 years ago. My entire collection is on this iPod, and I would like to have it available on my iPhone without having an Apple Music subscription; I do not see the point in paying to listen to music I bought at a record store twenty or thirty years ago. And I am worried about what to do when the battery of this iPod finally dies and one is not available. Advice or suggestions? I just spent an hour on the phone with Apple Support and was put on hold for ten minutes but needed to hang up. The support staff were great but unable to help before I needed to go. So, here I am asking the community! Thanks in advance!