When you arrive, register with your local Children's Centre (assuming that's not just an England thing) and you'll find lots.
Also a local facebook page for the area you live in should point you in the direction of lots of things as well. 
It’s an England thing. 😂😂😂
There’s tonnes of stuff on so I would suggest finding the local Stockbridge Facebook page, or sometimes there’s a ‘Whatevertown Mums’ group as well. What to look for is a toddler group, that’s where to have a relaxed, inexpensive time, and to meet friends. And to get the lowdown on what’s good in your area.
I’m across the water in Fife and can help you when you get here if you’ve got any other questions. Don’t hesitate to get in touch.
