Look around you in the Meeting!
Everyone there is a minister of the Spirit within. That is why someone may be guided to stand and give an inspired message, and so aid and serve worship and wisdom for all there.
In order to give pastoral care to members and others who attend, most Meetings appoint a small group to serve as Ministry and Counsel, and these may be the folks whom you see starting and closing the meeting and doing readings. Feel free to talk to one of them with your questions.