Answer
Treat the decision as a small piece of due diligence. For traveller meetups and social groups, ask about clear purpose, public venue, organiser identity, group size, language, privacy, transport, cost, code of conduct and how last-minute changes are communicated.
Record the answers that matter to you and make sure any confirmation reflects them. This is particularly important when transport, children, equipment, dietary requirements or weather can change the experience.
Use a public, established venue and avoid sharing sensitive travel or accommodation details in an open group. A specific theme usually creates a better event than a vague invitation.
Reconfirm shortly before arrival if the plan depends on a schedule, event, tide, weather condition or limited availability.