Hopefully, it's AC voltage
Try setting it for the lowest AC voltage , my freebie's starts at 200Vac but will show all the way down to 1.5Vac with a sustained output such as a transformer.
I normally much prefer the "swing needle" types they show pretty quick!
A easier way for you could be to use a drill, just chuck it in, spin it up! ATM it won't matter the RPMs you just want to know that it's producing output. Next step would be to know the RPMs , and voltage.