Once my Apple Music subscription ends, can I use iTunes to continue listening to music?

Deep down in the legal documents: Legal - Apple Media Services - Apple you will find, "When your Paid Subscription to any Service ends, you will lose access to any functionality or Content of that Service that requires a Paid Subscription."

If you are asking about Apple Music tracks that you downloaded for offline use, when your subscription end the tracks will not play. If you purchased the music, they will play.