Do you need a chairperson?
Some groups don't have a formal role of chair, or a named chairperson. However, even very small or informal meetings need some direction and organisation.
You could decide to rotate this role. This has the advantage that it spreads the responsibility and gives everyone a chance to be involved with the running of the group.
A potential disadvantage of rotating the chair is that no one takes responsibility for the role, or that the same person always ends up chairing without a proper agreement about this.
If you do decide to have a rotating chair, work out collectively what is expected of them and agree from the end of each meeting who will chair the next one. This gives them the opportunity to think about the meeting and their role in it.