I really can’t recommend the website, Meetup, highly enough. I use it at home and abroad to find groups of people getting together for all sorts of activities. Creating an account is free and easy and it’s rare to come across a town or area that has no communities set up on it.
You can search activities or groups on the website based on your dates, location or interests and I’ve always found them warm and welcoming towards new members. I’ve tagged along to all sorts of things, from yoga lessons to board game evenings and from mountain hikes to art classes and I’ve never been disappointed. Some of the activities have a small fee involved depending on whether they’re renting a space or paying a teacher to come in but, usually, the get-togethers are cheap or free and they’re always great fun!