If you have problems using the iTunes Store on Mac
If you’re unable to browse, sign in to, or buy music from the iTunes Store in the Music app on your Mac, try the following:
If you see a message that your computer can’t connect to the iTunes Store, click iTunes Store again. (If you don’t see iTunes Store in the sidebar, choose Music > Settings, click General, make sure iTunes Store is selected, then click OK.) If your computer still doesn’t connect, make sure your internet connection is working—open a web browser and visit a website. If your internet connection is OK, there may be a problem with the iTunes Store. Try visiting the store again later.
Make sure your computer’s date, time, and time zone are set correctly.
Make sure your account information is accurate and that you don’t need to correct a problem with a previous purchase. Choose Account > Account Settings, then sign in (if necessary). To verify your account information, click Manage Payments next to Payment Information.
Make sure the iTunes Store is available in your country or region. See the Apple Support article Availability of Apple Media Services.
If you can’t find the song or album you’re looking for, it may not be available for sale. Visit the iTunes Store Requests website, then visit the iTunes Store at a later date to see if the song or album is available.
If you’re still having trouble using the iTunes Store, visit the Billing and Subscriptions website.