I can't reply re LC, but ABA volunteering is not LC-ing.
You can just come along and help out. you can take on a group role. You can train to become a qualified breastfeeding counsellor or community educator.
You can read more about training here.
Counsellors do take shifts on the helpline as part of their volunteer role. It's not an option to not do it if you do the training. But as mentioned above, there are other ways to volunteer if that isn't your thing.