Old Purchases on iTunes Missing

Hello,

I have recently purchased a new iPhone 12 Pro and i noticed that some of my older music is not syncing up. I can't get my music to redowload and it has showed that my Mac iTunes is not allowing me to link up my iCloud and has created a mess with missing purchases not being able to download and share between my devices. I have set up all the setting and have gone into iTunes Purchase history and still they are not showing up as downloaded. For Example, i have a purchased song from 50 Cent that i purchased on Aug 30,2009 "In Da Club" that does not show in my iTunes or on my Phone but when i search that song as if i wanted to re purchase it shows a tab that says Purchase but i can't get that song to re download, This is very frustrating and i have never had this issue before. There are other songs that are not showing up on my iTunes.