Glad to see this happening! I would like to point you to ROpenSci’s Code of Conduct as a potential resource. An immense amount of effort went into that CoC, and it’s becoming a de facto standard for R conferences and events. ROpenSci also hosts community calls and training events where they share information on effective enforcement of a CoC. We used their CoC at the Chicago R Unconference 2019, and sat in on some of the community calls and found it all quite useful.
Merely as an anecdote, having a CoC felt very abstract until we worked out the enforcement process in gory detail. Who makes CoC enforcement decisions? Is that a consensus process or does one person take the lead? What are the most likely CoC violations? What are the consequences for these violations? How I am going to tell someone who I might know and be friends with that their behavior is unacceptable? I would encourage you to similarly spend time organizing enforcement procedures, because we didn’t feel ready to actually run our event until we had put about as much effort (or more) into the enforcement procedure as into the CoC itself.
Hopefully this is helpful in your planning. Thanks again!