Assuming you're in the U.S., 1) connect with your local intactivist group and see where you can plug in, and 2) never let a woman tell you she's pregnant without speaking up about circumcision.
The decisive conversations tend to be between ill-informed/profit-seeking doctors and pregnant women. There's also a second level between circumcised fathers and pregnant wives.
Cracking those intimate conversations is difficult but not impossible. You do have to be alert, courageous, and caring, without coming across as desperate or fanatical.
Some parents will try to project their discomfort onto you by accusing you of being weirdly interested. That's on them; don't let it stop you from trying with the next parent.
Opportunities through intactivist groups include baby fairs, where expecting moms show up looking for information and freebies. If you're not comfortable talking to the moms (not everyone is, and not every mom wants to have the conversation with a strange male), help with setting up the booth and supporting the women staffing it.
