ok I get it...........you cannot select a group of files and change all the names or the track numbers. one at a time. So this should go to thread about tags.
Not in the tag window. You can do it in the details pane:
0. Switch your view to Details mode.
1. Select the files you want to change.
2. Hover your mouse over the field column (name or track #) that you want to modify.
3. Right click and choose
Rename (or hit F2)
4. Enter what you want to change them to into the edit box that appears.
5. When you hit Enter or navigate away it will modify all the selected files to match.