Stacks are closed submixers, they expose just one channel (mix of channel plus 2 Fx channels). Stacks can be different for each Part.
Select your mic as Input (top right), choose some insert effects as you would do with any vocal channel, such as eq and compressors etc. Select one or two Fx (reverb, delay etc) in the fx channels and your’re done.
i really wouldn’t call this a tutorial, but rather a (very) quick overview at a glance.
much of the workflow and “what things even are/do” is still a mystery to me… that’s a shame, there is NO (real) documentation of this program, is that right? do we have to figure everything out by ourselves?