Hi @Anonymous_d8afad4f612e300099866f9c192f4755 good on you for starting to organise a meetup, you should also make a meetup entry here https://maps.google.com/localguides/meetup so that important details like location, time and date and a description of your proposed Meetup are known to everyone who might like to come along.
Have a read of How to Organise a Local Guides Meetup and HowTo: Leading a Photo/Food/Geo Walk (which would work just as well for beach volleyball). You would need to think of some way to tie it into Google Maps and/or Local Guides.
I hope your Meetup goes well.
Regards Paul