Didn't end up going today. I am going Monday instead. I can ice skate extremely well. It's pretty much the same thing except for the surface area right? Obviously the tips of the skis and length make it different but same thing for turning and stopping the same as hockey stopping.
Stopping will be exactly the same. I doubt the length will matter that much if you have a lot of hockey stop experience, just commit. You'll also find that becoming comfortable with how wedge shapes control speed is useful (particularly if you get behind some huge group of slowbies on a flat area and don't want to blow your speed by hockey stopping). I mean, you can skate on skis and it's kind of fun, but way easier to carry momentum. As for actual parallel turns it'll probably just depend. It won't hurt to tell the instructor that you have ice skating experience since they do tend to be pretty similar.