One of the ways Ive seen organized groups handle this is to offer an "escort" of sorts for your first munch. The groups Ive known have had one or two people whose responsibility at a munch is to make new people comfortable in the new setting. Typically, they will meet you outside of the munch location (parking lot?) saying " hi, Im so and so from the munch" and offer to literally walk you in, so that youre not completely alone there. Many times, there will also be two or three people there who will offer to sit with you, introduce you around, and make sure that you dont end up in the deep end of the swamp before youre ready. From my experience, these munches are very low pressure events, there's no blatant collars or cuffs, no semi naked subs wandering about, and such. Its just literally a vanilla gathering of people with like minded interests who get together to chat, exchange ideas and generally get comfortable around one another before going to anything like a "play event". In the same way, its also a way for group members to get an eyeball on you and at least see that youre not an axe murderer or a reporter, at least at first glance

Hope that this helps you somewhat,
Mr R