wheels on a trainer

My best piece of advice is to use a dedicated trainer tire and to never, ever use the same tire on the trainer as you do on the road.  It's potentially dangerous.  The trainer will wear down the tire and square off the center part of the tire that makes contact with flywheel roller.  There's a reason tires are rounded and not squared.

So a dedicated trainer tire can be an old used tire or a trainer tire.  I'd suggest a trainer tire.  They are unbelievably durable.  They will last years.  A regular tire on a trainer isn't going to last that long.  Continental, Cycleops, Kurt Kinetic, Vittoria all make trainer tires.

You're right on with your thinking.  My next suggestion is to get a cheap dedicated rear wheel to put the trainer tire on so that you're not swapping out tires for the road and trainer.  That will get cumbersome.

Don't mix up the terms wheel and trainer.  The wheel is the rim, spokes, hub.  The tire is the rubber that goes on the wheel.  They are two separate and distinct things.  You want a dedicated wheel plus a trainer tire.

Swapping out wheels is very easy and a good skill to learn.  Swapping out tires can be extremely difficult depending on the tire and wheel.  A trainer tire is going to be very, very difficult to get on and off a wheel.  Hence why you don't want to be swapping tires every time you switch your bike between road and trainer.

This is why I'm a huge proponent of direct drive trainers vs wheel-on trainers.  Direct drive trainers are so much less fuss.  Downside is they're more expensive.