There should be a fellowshipper at every teaching appointment. It is almost always better to have one. After full-time missionaries make appointments in your ward, they will email (or text) you about it. You would then find a ward missionary (or other ward member) that is best suited for the person and commit them to going with the full-time missionaries.
Once you have found someone and committed them to coming, make sure that the full-time missionaries know who it is and their contact info.
Note: Full-time missionaries need someone who is of the same sex and over 18 present.
