Congrats on your first Foxtrot lesson as it is a great dance; one of my most favorites. And, indeed if you are this new to dancing, welcome to the community.
As for promenade with spin, there is no such a thing. As you commence to spin from PP, as a leader, you cut in front of the follower, so you get back into dance position, as she steps right into you and powers the pivot. If you chose to do multiple pivots, then partners stay in the dance position and exit in the either closed or PP.
Just the pure physics of the pivoting motion and the need for oppositions within the partnership, makes it impossible or utterly uncomfortable and unnatural to pivot in PP.
I hope this helps………..r.