Congratulations on climbing aboard. I've done the same thing, and paired a Z6 with my D850. I use both side-by-side. I still prefer the D850 for BIF and fast action but otherwise use them interchangeably.
I too started only with my F-mount lenses and the FTZ. I now have a couple Z-mount lenses (the 85mm and the 24-70 f/2.8), but more typically take both cameras on an outing and select a lens for each camera from my F-mount glass.
I'm sure you won't be disappointed.
Kevin
"To photograph; it is to put on the same line of sight the head, the eye, and the heart." Henri Cartier-Bresson
I too started only with my F-mount lenses and the FTZ. I now have a couple Z-mount lenses (the 85mm and the 24-70 f/2.8), but more typically take both cameras on an outing and select a lens for each camera from my F-mount glass.
I'm sure you won't be disappointed.
Kevin