How do I transfer iTunes library from Windows laptop to iPhone 15 and iPad?

I have a large itunes library consisting of some purchased itunes songs and (mostly) hundreds of CD's that I imported into the library.

It resides on a Windows laptop, and on my old iphone (10 I think).

I recently bought an iphone 15 that has plenty of storage for the library, but I have been unable to transfer the library from my laptop to the new phone. Nor have I been able to figure out a way to transfer this library from one phone to the other.

I got a ipad generation 10 for Christmas and am having the same issue.

It used to be when I'd get a new phone, or even added music to the library, I could hook the phone to the laptop via cable, the laptop would recognize the device, and I would synch the phone with the master library.

Now the itunes menu has changed and I don't see that option.

As it stands, my old iphone is basically an ipod, and the newer devices, although they have itunes or Apple music on them, contain only about 1% of the library.

FYI, I do not subscribe to Apple music. I already have Sirius, Spotify, and Prime Music. But I would subscribe at least temporarily if I could get my entire library on at least one of the two mew devices.

Thank you!

[Re-Titled by Moderator]