Is there a trainer with an odometer?
Odometer doesn't matter. You can set it to light pressure and get lots of "miles", or you can set it to heavy pressure and not go as far. Similar to counting miles on the road- riding on the flats vs doing serious climbing.
Measuring hours is a better rough metric.
What's a good trainer? The pluses for more money.
If you want to spend more money, it's hard to beat the KICKR. And it's worth it.