Be committed-turn up on time; do any work you have promised to do; and persevere with the group even if there are problems. Try to find solutions to these problems.
Play to your strengths-find something you can contribute. For example,if you don't feel confident doing presentations,instead volunteer to produce the handouts.
Be inclusive-help all group members to feel involved. If someone is not participating, try asking their openion or seeing if there is a role they'd like to take on. Try making them feel welcome by chatting before or after the group meets.