Just bought MacBook Pro. How do I get my music from iTunes to synchronize to Mac from phone.

If all of your music on your iPhone was purchased through iTunes, you should be able to redownload your purchases directly in the Apple Music app on your Mac. This site will help: https://support.apple.com/en-gb/HT211816

If you have other music on your device, and had synced with a different machine, you have a few options:

1. Find the library contents (your music) on the other machine, copy the folder contents, and then import it into your Mac Music App. If you will no longer use this device, be sure to deauthorize it too. https://support.apple.com/guide/music/import-items-already-on-your-computer-mus3081/mac. A common example is transferring files from a PC to a new Mac using migration assistan thttps://support.apple.com/en-us/HT204926. Once completed, and when your music is on the Mac, simply sync your device. https://support.apple.com/en-us/HT201253
2. Subscribe to either iTunes Match or Apple Music. Your music on device will then be uploaded or matched and synch across all of your devices. https://support.apple.com/en-us/HT204146. https://support.apple.com/en-us/HT204926.

You can still sync music on your Mac to your iPhone, without subscribing, simply by using finder. But, this will sync music in your Mac library onto your device. And, you need to have music on your Mac first.