It's generally not as easy as that Pookie,
You need to write to and visit local farms offering your services as a pest control
shooter. Be prepared for loads of knock backs. It generally takes ages, but who knows
you might just be lucky and fine one straight away.
You might want to join a club and maybe a generous member might let you tag along
on one of their shoots.
Shooting ground is highly prized and generally not easy to come by.
Good luck
Nealsey