You don't ask people on here to tell you where you can go with permission...
you need to go round to the farms and places with land and politely ask them to control the rabbits there,and perhaps offer to do work for them in return.
Make sure you are polite and don't dress up like a little chav,that will give the wrong impression - let them know you do know what you are doing (if you do...) and you can be trusted,depending on age it could be a good idea to take a parent so they know you will be responsible,i'm sure there are topics saying how to get permission about,also check the "fieldsport