on meetups the etiquette is a little different since you are all already "vrg" so it's like being on a same group so it's lot less formal, for meetups i would recommend
1. walk up to people and wave at them a greeting or say something akin to "yo what's up" or "hi"
2. if people noticed you go for a headpat greeting
3. hover around groups that are talking until a topic you can join in on emerges
4. wait for your turn and give your input on topic (your turn is when there is room to give a opinion on the topic, remember others are waiting for turn to give their two cents too so don't take all the pauses for yourself)
alternatively you can just find someone who enjoys headpats and maybe cuddling and go exchange headpats with them, word of warning prolonged headpats may lead to solicitations of erp so if you're not into that shit keep them brief