Need to make new friends and get out?

Felling isolated and frustrated with my life. Divorced and every other weekend my children have to go and spend time my ex, having just moved into the Leicestershire area I don't know anyone. I want to meet people and let my hair down. I'm in my early 40's but everyone says I look mid 30's and just want to have some fun with a group of people going out and building a foundation of friendship- any thoughts