New apple-id for my IPod 4.2.1

That will not help.

That's a very old iPod and there are unlikely to be any apps in the store that you can use. The last time I made a note of the requirements (in February 2022), an iPod needed iOS 12.2.7.58 or later to be able to buy anything in the app store.

An iPod touch running iOS 4.2.1 might be one of

• iPod touch (2nd generation), for which iOS 4.2.1 is the end of the line.
• iPod touch (3rd generation), for which iOS 5.1.1 is the end of the line.
• iPod touch (4th generation), for which iOS 6.1.6 is the end of the line.

All of these are 32-bit devices, limited to ancient versions of iOS.

I don't think any of them would be able to access the App Store – or, if they could, if you would find very many apps that are compatible with them there. (Even the Apple Music app requires iOS 10.0 or later.)

I don't remember the menus on the 2nd generation iPod Touch (which I believe is what you have if it's using iOS 4.2.1), but if you look in Settings you should see your account name somewhere on that menu.

You should be able to change it there but be very careful; if you have music purchased from the iTunes Store (with your existing account) it will be dependant upon your Apple ID. If you sign out of that account and create a new ID, you will lose access to the music you bought with the old ID.

Why do you need to create a new Apple ID?

I need to change, i e uppdate, my Apple-ID to be able to access appstore. The iPod has an old id that is no longer recognised by appstore.