I'd also not worry too much if you don't lose weight straight away - you may be replacing fat with muscle and the scales may not drop immediately. As others have said, it's important to measure yourself and take photos.
Good luck and well done for taking the step - you won't regret it.
Yes, nice to be back in the woods, though something may have to be done for the faster runners lapping people on their first loop. I thought the new location at the bottom of Cassiobury park worked well, though it was initially hard to see where the front and back of the start was. Overall though, really enjoyed it!