iTunes Still Charging per Track While Subscribed to Apple Music
The prices are shown because you are in the iTunes Store tab. You can still buy tracks and albums there, like before. To get to Apple Music, click "My Music", "For you" or "New" in the top bar.
"My music" is where your music is, both the tracks and albums you've previously purchased and the ones you've saved in Apple Music. "For you" is personalized suggestions, and "New" is well, new music.
When you do a search from any of those tabs you can also choose to search Apple Music instead of just your own library.