Hey,
On my Trainer is my road bike. If you have a road bike, use it. Better to have more closely spaced gears, even in erg mode. (Although when using erg it doesn’t matter as much what gears you have as the trainer handles power).
See this post:
I use the cadence recommendations in the TR instructions for most workouts. This is usually 85-95 for normal cadence, up to 120 for high spin work, and as low as 65-70 for slow work.