1st Tube amp question

You need stuff going in and coming out. Quality level isn’t critical… could be an iPad in and an old set of speakers.

You can damage the output transformers with no speakers connected.  This applies to all the tube amps I've used.    Won't hurt most transitor amps , but bad for tube amps

Tube amps need a load on the outputs, whether a speaker or resistor.

Everyone eventually accidentally turns on their amp without a load--well most of us at least.  

the problem occurs when you hear no music and turn it up, putting harmful currents into the transformers.  

If you keep the volume down or on mute or have no signal going in, you won't do any damage.  But there is no reason to do this other than by accident.  This won't help significantly with burnin although time on the tubes with heat will help them settle in.  I'd just wait and do it with music so you can hear the improvements.

Jerry

You don't necessarily need an input, but you do need a load on the output transformers.