You can view and edit the track information in two different ways.
1. When the track is selected, expand the 'Player' view to see the track details. To edit, click the '(i)' icon in the bottom left. The 'Track Details' will appear, tap the 'Edit' button to make changes.
2. In the All Tracks or Playlist views, you can select the three dots on the right-hand side of the track which will bring up the 'Track Details' view. Tap the 'Edit' button to make changes.