Music missing on new MacBook Sonoma

Hello.

I had a MacBook Pro when I was working years ago and when it died I got a Lenovo Yoga as I didn't have the funds for a new Mac.

last month I purchased a MacBook Sonoma from Best Buy and their Geek Squad transferred everything to my Mac. Or so I thought.

The iTunes file on my new Mac only consists of about 30 albums out of hundreds I had added over the years. Some from the iTunes Store and some from CD's I had copied.

I could kick myself for going to Best Buy rather than the local Apple Store which is located in the local mall but mobility is an issue for me and I just didn't have the energy to hit the mall.

I have no idea why all the albums didn't copy.

Is there a location on my Mac I can check or any other suggestions will be greatly appreciated.

Thanks much and stay safe out there.