Your Questions About Rough Collie Breeders

How to find a reputable Collie breeder?

My family and I are looking for a rough collie breeder. I’ve been looking at websites, but my parents seem to find a flaw in every breeder we look at lol. How do you tell if a breeder is good or bad? I know to make sure they health test/show/etc, but what are some other things?

Or, does anyone know any good breeders in California? Thanks.
We already have one adult dog that we got from the shelter. We want to purchase a puppy from a breeder this time.

Will a 16 months dog adapt to a new family?

I have never owned a dog before so I’ll be needing lots of advice on this topic. I’m thinking of adopting a 16 month old female Rough Collie. Her previous owner is a reputable Rough Collie breeder that wants a new family for her. Will it be really hard for her to adapt to a new family? I just called the breeder up and she told me I might have to give more attention to her for changing her family. Should I find a puppy instead or adopting is better for a first time dog owner?

if i buy a rough collie puppy from a breeder what vaccines will it need?

hey everyone
i have found nothing about this anywhere and my dad needs to know before i buy, will the breeder already have gave them there first jabs? will they tell me what to get them?
or do i go straight to a vet and ask them, can they tell what they already had jab wise?
how often does a rough collie need vacines, im guessing every 3 years?
much appreiated