You will be in LA?
• Everyone should have a few copies of the tri-fold Open Carry pamphlets, detailing Penal Codes, where's it's legal, when it's legal, etc.
• Everyone should have their audio/video recording if this meet migrates from inside a private place to outside, AND if LEOs show up.
• Try to have non-carrying friendly witnesses attend too.
• Know that most LEAs in LA/County are anti-carry.
Hope for the best, but prepare for the worst.