
On the form it will say if the show is judged on the Group system.
If there are Sibe classes, what ones are there. If there are none, you will need to enter in Not Seperately Classified Working (if on Group system) or just plain NSC if not on Group system. Under these breed headings will be one or more classes you can enter.
There are also likely to be Variety classes, like Any Variety Working, or Any Variety Puppy etc.
I would advise entering say 3 classes, the lowest in each section that you are eligible for. this will give you and the dog more experience in the ring, as if you only go for one class and you are alone, or only one or two of you, then it will all be over before you find your feet.