yes Hello Sid, and welcome to the best allotment site on the internet! You will certainly get a lot of good advice here, but it is my opnion that you should remove the turf layer first before rotavating. This can be done by cutting the turf into blocks with a spade, then slicing them off. They should be stacked turf side down to rot and produce a good material for returning to your plot.
Once your allotment association has started, I am sure more people will become interested.
Good luck
Derekthefox :D