During the signup process, you're asked if you'd like to start your free three-month trial. Part of that process is you agreeing to pay for Apple Music once your trial expires, with no further action required on your part.
Apple Music, TV+, and Apple One are getting a price increase.
If you want the best listening experience possible, it's time to enable lossless audio on Apple Music. We'll show you how here.
It's also replacing users' default music app.