Do I use the motion effect BEFORE I import it to the time line sequence (i.e. while in the preview windows Project Explorer)?
Place the clip in the Timeline, then with the clip selected
open the Effect Controls and apply the Motion Effect > Scale:
Once scaled, you can also use the 'Position' control to
slide the clip left or right to improve the framing if needed.
Premiere Pro / Motion: position, scale, and rotate a clip
You must do this for a living