How do i know if my Apple Music account is deleted?

I think here you mean cancel the Apple Music subscription. You can conduct the following operations:

1. Open the Settings app. 
2. Tap your name, then tap Subscriptions.* 
3. Tap the subscription that you want to manage. 
4. Choose a different subscription option, or tap Cancel Subscription. If you don’t see Cancel Subscription, the subscription is already canceled and won't renew.

Hope it helps.