For SEO agency owners

So I’m thinking of starting a SEO agency, and I have some questions. I know these might sound dumb, but I don’t contain the knowledge of what the answers are, and you got to find out one way right?

• Do I need to study SEO for a while before starting out, even if I’m going to hire a contractor?

• Do I need access to the client’s website, or what info does the client need to give me?

Thanks a lot, all responses are highly valued!