Hey Sonya! Try this:
•Duplicate your timeline (to save the previous version).
•Open your Project settings (Command J).
•Change the video format to “Custom” and resolution to something square, like 640×640.
•Open your new timeline, select all, and set the Spatial Conform to “Fill.”
•Adjust clips as needed in the Inspector (use the X position to slide an image left or right to get the correct framing.
That should get you close, very quickly. Let me know if that works.
Cheers,
Bill