The most useful first conversation is usually thirty minutes about what your stakeholders actually decide. Not a demo.
It is also where a PBI session starts. If you can answer it in a sentence, you are further along than most teams. If you cannot, that is the finding, and it is worth knowing before anyone builds anything.
The index is open and ungated at mrsindex.com, and there is a live example of the Brief on this page. Both will tell you more about how this works than a call will.