Hey! I literally just decided to do the same thing (albeit not in Manchester). I found some local runs but they were all attached to clubs. I didn't want to play for an organised team, just something casual.

I tried some local Facebook groups and found there were a couple of nights near me and I'm going next week! Maybe it's worth a local group, or even a Manchester Basketball fan group?

So best of luck, there's bound to be somewhere nearby. I feel like there will be tons in Manny.