answer:
Joining a Meetup Group is pretty simple. When you come across a Meetup Group you'd like to join, click the Join us! button.

You'll be taken to a page that will ask you to
fill in your Group profile for that Meetup Group. You may need to add a photo or answer a few
questions, depending on how the particular Meetup Group you want to join is set up.
Most Meetup Groups are open to anyone, though some Meetup Groups require Organizer approval before new members can join. If that's the case, you'll see a message letting you know that the Organizer has been notified once you've submitted your profile:
Thanks! Your information has been saved and your request for membership has been sent to the Meetup's Organizer. You should hear back shortly.
In the meantime, would you like to explore some other groups in your area?
You'll receive an email when your membership in that Meetup Group has been approved.If you haven't already registered a Meetup account, you'll need
to create one before you can join any Meetup Groups.
And if you have an account but you aren't logged in, you'll need to
log in before you can join the Meetup Group.