
Some things will be breed dependent.
Talking to the judge unless asked a question is not allowed, but a few words often set you at ease. Nothing wrong with saying your new to all this and can he make his instructions very clear, though often better to say this to the steward checking the class.
It is best to arrive at least an hour before your likely to be judged. Dogs are supposed to be on their benches except when being exercised (actually a euphemism for going for a toilet break), or being groomed or during exhibition.
if your benches are some way from your ring it is usual for people to bring their dogs to ringside, at least for that sex. I show bitches so will not take mine to the ring until Open dog goes in.
As for dress in some breeds casual is fine as long as it is clean and decent, in other breeds everyone wears a suit and others anything between, so seeing what is the norm in your breed is a good idea.
What you do want to ensure is that the colour fo your bottom half is one the dog shows up against, and contrasts nicely. For example some colours do not flatter some breed colours.
As for handling styles, free standing (my breed) stacking (many gundogs), some are even presented front on, adn soem smaller breeds are stood on a table.
Even the way you move your dog, loose lead (but some breeds hold the lead up high, (sadly some string them up so the front feet barely touch the ground).
You should have been advised fo this at Ring craft and been practising that style fo ring presentation.
Style of coat presentation is also something to bear in mind.
For example someone new to our breed came to a show with me. When we were giving the dogs a final groom, I noticed that she was back-combing and fluffing up her pups coat, making ti look like a meringue. I quickly Had to tell her that the breed is required to have a dense but close coat. So we quickly had to comb it all through and slick it down (she had a profuse puppy coat).